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Sample records for ieee trans magn

  1. 21 Effet magnéto-optique et optique des couches minces à base de ...

    African Journals Online (AJOL)

    albatha

    Magneto-optical effect and optical thin films cobalt ferrite ... Keywords : cobalt ferrite, sol-gel thin films, Faraday rotation, transmittance. .... [3] - R. MASSART, « Preparation of aqueous magnetic liquids in alkaline and acidic media» IEEE Trans.

  2. IEEE Smart Grid Series of Standards IEEE 2030 (Interoperability) and IEEE 1547 (Interconnection) Status: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Basso, T.; DeBlasio, R.

    2012-04-01

    The IEEE American National Standards smart grid publications and standards development projects IEEE 2030, which addresses smart grid interoperability, and IEEE 1547TM, which addresses distributed resources interconnection with the grid, have made substantial progress since 2009. The IEEE 2030TM and 1547 standards series focus on systems-level aspects and cover many of the technical integration issues involved in a mature smart grid. The status and highlights of these two IEEE series of standards, which are sponsored by IEEE Standards Coordinating Committee 21 (SCC21), are provided in this paper.

  3. IEEE Prize for Lucio Rossi

    CERN Multimedia

    IEEE Council on Superconductivity

    2007-01-01

    Lucio Rossi receives his prize from John Spargo, Chairman of the IEEE Council on Superconductivity (left), and Martin Nisenoff, Chairman of the Council on Superconductivity's Awards Committee (right).

  4. MagneMotion urban maglev : final report

    Science.gov (United States)

    2004-11-01

    The MagneMotion Urban Maglev System, called M3, is designed as an alternative to all conventional guided transportation systems. Advantages include major reductions in travel time, operating cost, capital cost, noise, and energy consumption. Small ve...

  5. Access to IEEE Electronic Library

    CERN Multimedia

    2007-01-01

    From 2007, the CERN Library now offers readers online access to the complete IEEE Electronic Library (Institute of Electrical and Electronics Engineers). This new licence gives unlimited online access to all IEEE and IET (previously IEE) journals and proceedings as well as all current IEEE standards and selected archived ones. Some of the titles offer volumes back to 1913. This service currently represents more than 1,400,000 full-text articles! This leading engineering information resource replaces the previous service, a sub-product of the IEEE database called 'IEEE Enterprise', which offered online access to the complete collection of IEEE journals and proceedings, but with limited features. The service had become so popular that the CERN Working Group for Acquisitions recommended that the Library subscribe to the complete IEEE Electronic Library for 2007. Usage statistics for recent months showed there was a demand for the service from a large community of CERN users and we were aware that many users h...

  6. Technical Training: MAGNE-04 : Magnétisme pour l'Electrotechnique

    CERN Multimedia

    Monique Duval

    2004-01-01

    Phénomènes magnétiques, matériaux et applications MAGNE-04 est un cours dans le cadre du programme de l'Enseignement Technique qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l'ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. En ayant organisé des sessions au CERN, une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur leur site en Isère. MAGNE-04 s'intéresse, entre autres, au développement de la compréhension des phénomènes magnétiques et le « sens physique » appliqués à des produits industriels. Programme : Notions de base en électromagnétisme. Les aspects électrique et mécanique du magnétisme. Les régi...

  7. CERN Technical Training 2005: MAGNE-05 - Magnétisme pour l’électrotechnique

    CERN Multimedia

    Davide Vitè

    2005-01-01

    Learning for the LHC ! Phénomènes magnétiques, matériaux et applications MAGNE-05 est un cours dans le cadre du programme de l’Enseignement Technique qui s’adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l’ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. Une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur le site de CEDRAT en France. MAGNE-05 s’intéresse, entre autres, au développement de la compréhension des phénomènes magnétiques et au « sens physique », appliqués à des produits industriels. Programme : Notions de base en électromagnétisme. Les aspects électrique et mécanique du magnétisme. Les régim...

  8. CERN Technical Training 2005: MAGNE-05 - Magnétisme pour l'électrotechnique

    CERN Multimedia

    Davide Vitè

    2005-01-01

    Learning for the LHC ! Phénomènes magnétiques, matériaux et applications MAGNE-05 est un cours dans le cadre du programme de l'Enseignement technique qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l'ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. Une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur le site de CEDRAT en France. MAGNE-05 s'intéresse, entre autres, au développement de la compréhension des phénomènes magnétiques et au « sens physique », appliqués à des produits industriels. Programme : Notions de base en électromagnétisme. Les aspects électrique et mécanique du magnétisme. Les régimes variab...

  9. CERN enseignement technique 2005: MAGNE-05 - Magnétisme pour l’électrotechnique

    CERN Multimedia

    Davide Vitè

    2005-01-01

    Learning for the LHC ! Phénomènes magnétiques, matériaux et applications MAGNE-05 est un cours dans le cadre du programme de l’Enseignement Technique qui s’adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l’ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. Une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur le site de CEDRAT en France. MAGNE-05 s’intéresse, entre autres, au développement de la compréhension des phénomènes magnétiques et au « sens physique », appliqués à des produits industriels. Programme : Notions de base en électromagnétisme. Les aspects électrique et mécanique du magnétisme. Les régi...

  10. CERN Technical Training 2005: MAGNE-05 : Magnétisme pour l'électrotechnique

    CERN Multimedia

    Davide Vitè

    2005-01-01

    CERN Technical Training 2005: Learning for the LHC ! MAGNE-05 : Magnétisme pour l'électrotechnique Phénomènes magnétiques, matériaux et applications. MAGNE-05 est un cours dans le cadre du programme de l'Enseignement technique qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l'ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. Une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur le site de...

  11. CERN Technical Training 2005: MAGNE-05 : Magnétisme pour l'électrotechnique

    CERN Multimedia

    Davide Vitè

    2005-01-01

    CERN Technical Training 2005: Learning for the LHC ! MAGNE-05 : Magnétisme pour l'électrotechnique Phénomènes magnétiques, matériaux et applications. MAGNE-05 est un cours dans le cadre du programme de l'Enseignement technique qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l'ensemble du personnel technique et scientifique ayant besoin d'une formation en magnétisme dans le cadre de leurs activités professionnelles actuelles ou futures. Une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur le site de CEDRAT e...

  12. IEEE Conference Publications in Libraries.

    Science.gov (United States)

    Johnson, Karl E.

    1984-01-01

    Conclusions of surveys (63 libraries, OCLC database, University of Rhode Island users) assessing handling of Institute of Electrical and Electronics Engineers (IEEE) conference publications indicate that most libraries fully catalog these publications using LC cataloging, and library patrons frequently require series access to publications. Eight…

  13. Researching the roots of IEEE Region 8

    NARCIS (Netherlands)

    Bastiaans, M.J.

    2013-01-01

    This paper describes the preliminary steps towards the foundation and the early history of IRE Region 9 / IEEE Region 8. The information has been gathered mainly from the archives of the IEEE Benelux Section.

  14. 2012 IEEE Vehicular Networking Conference (VNC)

    NARCIS (Netherlands)

    Altintas, Onur; Chen, Wai; Heijenk, Geert; Oh, Hyun Seo; Chung, Jong-Moon; Dressler, Falko; Kargl, Frank; Pau, Giovanni; Schoch, Elmar

    2012-01-01

    On behalf of the Organizing Committee, we would like to welcome you to the fourth edition of the IEEE Vehicular Networking Conference in Seoul, Korea. IEEE VNC is a unique conference sponsored by both IEEE Communications Society and Intelligent Transportation Systems Society. It brings together

  15. CERN Technical Training 2005: MAGNE-05 : Magnétisme pour l'électrotechnique

    CERN Multimedia

    Davide Vitè

    2005-01-01

    CERN Technical Training 2005: Learning for the LHC ! Phénomènes magnétiques, matériaux et applications. MAGNE-05 est un cours dans le cadre du programme de l'Enseignement Technique qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l'ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. Une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur le site de CEDRAT en France. MAGNE-05 s'intéresse, entre autres, au...

  16. IEEE Prize for Lucio Rossi

    CERN Multimedia

    2007-01-01

    Lucio Rossi receives his prize from John Spargo, Chairman of the IEEE Council on Superconductivity (left), and Martin Nisenoff, Chairman of the Council on Superconductivity’s Awards Committee (right). (Photo: IEEE Council on Superconductivity)With the magnets installed in the tunnel and work on the interconnections almost completed, Lucio Rossi has reaped the rewards of fifteen years of work. And yet, when the physicist from Milan arrived to take charge of the group responsible for the superconducting magnets in 2001, success seemed far from assured. Endowed with surprising levels of energy, Lucio Rossi, together with his team, ensured that production of these highly complex magnets got underway. Today, that achievement earns them the recognition not only of CERN but also of the international superconducting community. It is for this achievement that Lucio Rossi was awarded the prize by the IEEE’s (Institute of Electrical an...

  17. Trans* Leadership.

    Science.gov (United States)

    Jourian, T J; Simmons, Symone L

    2017-06-01

    Focusing on emerging literature on trans* and gender-nonconforming students and their leadership, this chapter outlines the ways trans* students are engaged in leadership in educational institutions and outside of them and discusses implications for staff and faculty regarding how to support and engage these students and their leadership. © 2017 Wiley Periodicals, Inc., A Wiley Company.

  18. CERN Technical Training 2005: MAGNE-05 - Magnétisme pour l’électrotechnique

    CERN Multimedia

    Davide Vitè

    2005-01-01

    If you wish to participate in one of the following courses, please tell to your supervisor and apply electronically from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an 'application for training' form available from your Departmental Secretariat or from your DTO (Departmental Training Officer). Applications will be accepted in the order in which they are received. Learning for the LHC ! Phénomènes magnétiques, matériaux et applications MAGNE-05 est un cours dans le cadre du programme de l’Enseignement Technique qui s’adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l’ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. Une importante économie p...

  19. Árni Magnússon's rearrangement of paper manuscripts

    DEFF Research Database (Denmark)

    Stegmann, Beeke

    Árni Magnússon’s rearrangement of paper manuscripts draws attention to the early history of Árni Magnússon’s (1663-1730) manuscript collection. The thesis examines Árni’s extensive rearrangement of paper manuscripts, showing that he repeatedly altered the physical composition of codices in his...

  20. Mitigación de campo magnético de líneas de transmisión utilizando bucles pasivos

    OpenAIRE

    Cadavid, D. R. (Diego Raúl); Ramírez, D. A. (Diego Alejandro); Lopera, F. (Freddy); Correa, A. F. (Andrés Felipe)

    2009-01-01

    En este artículo se presenta un método simple para determinar el campo magnético generado por líneas de transmisión. El cálculo del campo magnético tiene en cuenta los efectos de mitigación de bucles pasivos, incluyendo su ubicación óptima en la línea mediante la aplicación de algoritmos genéticos. Los resultados de los cálculos son validados mediante reportes de casos publicados en el IEEE, software de análisis de campo electromagnético y datos experimentales arrojados de una implementación ...

  1. The IEEE Milestone event at CERN

    CERN Multimedia

    2005-01-01

    On the initiative of its French and Swiss Sections, the IEEE has honoured CERN with an 'IEEE Milestone in the history of electricity and electronics' for the invention of the multi-wire proportional chamber in 1968. The IEEE established the Electrical Engineering Milestones programe in 1983 to honour significant achievements in the history of electrical and electronics engineering. To be designated, an achievement must be at least 25 years old, must have involved a unique solution to an engineering problem, and must have had at least regional impact. Currently there are more than  50 IEEE Milestones around the world. http://www.ieee.org/organizations/history_center/cern.html The installation and unveiling of this IEEE Milestone will provide the opportunity to emphasize the close relationship between science, technology, industry and well-being in society.  A ceremony, organised with the support of a group of IEEE members working at CERN, will be held at the CERN Globe of Science and Inn...

  2. CERN receives prestigious Milestone recognition from IEEE

    CERN Multimedia

    2005-01-01

    At a ceremony at CERN, Mr W. Cleon Anderson, President of the Institute of Electrical and Electronics Engineers (IEEE) formally a Milestone plaque in recognition of the invention of electronic particle detectors at CERN

  3. IEEE International Symposium on Biomedical Imaging.

    Science.gov (United States)

    2017-01-01

    The IEEE International Symposium on Biomedical Imaging (ISBI) is a scientific conference dedicated to mathematical, algorithmic, and computational aspects of biological and biomedical imaging, across all scales of observation. It fosters knowledge transfer among different imaging communities and contributes to an integrative approach to biomedical imaging. ISBI is a joint initiative from the IEEE Signal Processing Society (SPS) and the IEEE Engineering in Medicine and Biology Society (EMBS). The 2018 meeting will include tutorials, and a scientific program composed of plenary talks, invited special sessions, challenges, as well as oral and poster presentations of peer-reviewed papers. High-quality papers are requested containing original contributions to the topics of interest including image formation and reconstruction, computational and statistical image processing and analysis, dynamic imaging, visualization, image quality assessment, and physical, biological, and statistical modeling. Accepted 4-page regular papers will be published in the symposium proceedings published by IEEE and included in IEEE Xplore. To encourage attendance by a broader audience of imaging scientists and offer additional presentation opportunities, ISBI 2018 will continue to have a second track featuring posters selected from 1-page abstract submissions without subsequent archival publication.

  4. CERN receives prestigious Milestone recognition from IEEE

    CERN Multimedia

    2005-01-01

    The Nobel prize winner Georges Charpak and W. Cleon Anderson, IEEE President, unveil the Milestone bronze plaques. At a ceremony on 26 September at the Globe of Science and Innovation, Mr W. Cleon Anderson, President of the Institute of Electrical and Electronics Engineers (IEEE) formally dedicated Milestone plaques recognising the invention of electronic particle detectors at CERN. The plaque were unveiled by Mr Anderson and Georges Charpak, the Nobel-prize winning inventor of wire chamber technology at CERN in 1968. The IEEE is the world's largest professional association dedicated to the advancement of technology with 365,000 individual members in over 150 countries. Established in 1983, there are currently over 60 Milestones around the world. They honour momentous achievements in the history of electrical and electronics engineering, such as the landing of the first transatlantic cable, code breaking at Bletchley Park during World War II, and the development of the Japanese Bullet train, the Tokaido Shin...

  5. The scalable coherent interface, IEEE P1596

    International Nuclear Information System (INIS)

    Gustavson, D.B.

    1990-01-01

    IEEE P1596, the scalable coherent interface (formerly known as SuperBus) is based on experience gained while developing Fastbus (ANSI/IEEE 960--1986, IEC 935), Futurebus (IEEE P896.x) and other modern 32-bit buses. SCI goals include a minimum bandwidth of 1 GByte/sec per processor in multiprocessor systems with thousands of processors; efficient support of a coherent distributed-cache image of distributed shared memory; support for repeaters which interface to existing or future buses; and support for inexpensive small rings as well as for general switched interconnections like Banyan, Omega, or crossbar networks. This paper presents a summary of current directions, reports the status of the work in progress, and suggests some applications in data acquisition and physics

  6. Editorial for IEEE Transactions on Power Electronics

    DEFF Research Database (Denmark)

    Blaabjerg, Frede

    2007-01-01

    Our IEEE transactions on power electronics has had some very positive progress these past years under the leadership of Dr. Daan van Wyk. Papers have been processed efficiently both in review time and publication time. This success has spread throughout the whole power electronics community which...

  7. The IEEE 802.11a standards

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. The IEEE 802.11a standards. Provides higher data rate and system capacities and uses OFDM in Physical Layer to mitigate the multi path effects;. Supports multiple 20Mhz channel. Each channel being an OFDM Modulated;; 52 Carriers. 48 data carrier; 4 Carry pilot ...

  8. Science and Technology of Nanostructured Magnetic Materials: Proceedings of a NATO Advanced Study Institute Conference Held in Aghia Pelaghia, Crete, Greece on 24 June -6 July 1990. NATO ASI Series B: Physics. Volume 259

    Science.gov (United States)

    1990-07-06

    C.N. Afonso, A.N. Lagunas , F. Briones and S. Giron J. Magn. Magn. Mat. 62 (1980) 833. B. Martinez, A. Ruiz, A. Labarta, X. Obradors, F. Briones...Magn. Mater. 50, 265 (1985). 35. T. Tokunaga, M. Harada, M. Ohkoshi, S. Honda and T. Kusuda, IEEE Trans. MAG-22, 940 (1986). 36. H. Heitmann, M

  9. Comment on “Performance of Halbach magnet with finite coercivity” [J. Magn. Magn. Mater. 407, 369–376 (2016)

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaonong, E-mail: xnxu@nju.edu.cn

    2017-05-01

    In the recent study given by Insinga et al. [J. Magn. Magn. Mater. 407, 369–376 (2016)], two kind of magnetic hysteresis loops, magnetization versus magnetic field strength (M-H), and magnetic induction versus magnetic field strength (B-H) of the permanent magnetic material with finite coercivity are involved. However, M-H and B-H functions are sensitive to the shape of magnetic element, moreover, M and B are possibly the multivalue functions at H=H{sub c}, perhaps the third kind magnetic hysteresis loop of magnetization versus magnetic induction (M-B) is more appropriate for predicting the phenomena of demagnetization and reversal of original remanence in magnet array. - Highlights: • Demagnetization is analyzed by the magnetic induction dependent remanence function M(B). • Partial demagnetization and remanence reversal may be distinguished by M(B) function.

  10. Nanopartículas magnéticas de zinc y calcio para aplicaciones en hipertermia magnética

    Directory of Open Access Journals (Sweden)

    Rosario Argentina Jasso-Terán

    2016-05-01

    Full Text Available El cáncer es la segunda causa de muerte en el mundo. El tratamiento alternativo de hipertermia magnética consiste en elevar la temperatura de las células cancerígenas por medio de nanopartículas magnéticas. En este trabajo se presenta la síntesis y la caracterización de dos ferritas de zinc-calcio (Zn0.50Ca0.50Fe2O4 y Zn0.25Ca0.75Fe2O4. La síntesis de estas ferritas se llevó a cabo por el método de sol-gel, con posterior calcinación a 400 °C. La ferrita Zn0.50Ca0.50Fe2O4 (ZCF050 presentó una magnetización de 31.31 emu/g, y la ferrita Zn0.25Ca0.75Fe2O4 (ZCF075, de 38.30 emu/g. El tamaño de partícula promedio fue de 14 nm para la ZCF050 y de 12 nm para la ZCF075. Adicionalmente, se realizaron pruebas de bioactividad in vitro mediante la inmersión de muestras en un fluido fisiológico simulado por 21 días bajo condiciones fisiológicas de pH y temperatura. Se encontró que solo la ZCF075 fue bioactiva. La habilidad de calentamiento de las ferritas se evaluó utilizando un equipo de inducción magnética en estado sólido. Las condiciones de trabajo fueron las siguientes: un campo magnético de 10.2 kA/m y una frecuencia de 362 kHz. La ferrita ZCF050 alcanzó una temperatura de 41.2 °C, utilizando una concentración de ferrita/agua de 20 mg/2ml. La ferrita ZCF075 no logró alcanzar los 40 °C. Los resultados obtenidos del análisis de la ferrita ZCF050 indicaron que es un material potencial para su uso en tratamientos de cáncer por hipertermia magnética.

  11. Trans-Planckian wimpzillas

    CERN Document Server

    Kolb, E W; Tkachev, I I

    2007-01-01

    Two previously proposed conjectures--gravitational trans-Planckian particle creation in the expanding universe, and the existence of ultra-heavy stable particles with masses up to the Planck scale (wimpzillas)--are combined in a proposal for trans-Planckian particle creation of wimpzillas. It is shown that the trans-Planckian particle creation parameter should be rather small to avoid overproduction of such particles. This ensures that wimpzillas are mainly created at the end of primordial inflation. Conditions under which trans-Planckian wimpzillas can constitute the present dark matter are determined.

  12. 7th IEEE International Conference Intelligent Systems

    CERN Document Server

    Atanassov, KT; Doukovska, L; Hadjiski, M; Jotsov, V; Kacprzyk, J; Kasabov, N; Sotirov, S; Szmidt, E; Zadrożny, S; Filev, D; Jabłkowski, J; Kacprzyk, J; Krawczak, M; Popchev, I; Rutkowski, L; Sgurev, V; Sotirova, E; Szynkarczyk, P

    2015-01-01

    This two volume set of books constitutes the proceedings of the 2014  7th IEEE International Conference Intelligent Systems (IS), or IEEE IS’2014 for short, held on September 24‐26, 2014 in Warsaw, Poland. Moreover, it contains some selected papers from the collocated IWIFSGN'2014-Thirteenth International Workshop on Intuitionistic Fuzzy Sets and Generalized Nets.The conference was organized by the Systems Research Institute, Polish Academy of Sciences, Department IV of Engineering Sciences, Polish Academy of Sciences, and Industrial Institute of Automation and Measurements - PIAP.The papers included in the two proceedings volumes have been subject to a thorough review process by three highly qualified peer reviewers.Comments and suggestions from them have considerable helped improve the quality of the papers but also the division of the volumes into parts, and assignment of the papers to the best suited parts.  

  13. IEEE 802.11 ECG monitoring system.

    Science.gov (United States)

    Tejero-Calado, Juan; Lopez-Casado, Carmen; Bernal-Martin, Antonio; Lopez-Gomez, Miguel; Romero-Romero, Marco; Quesada, Guillermo; Lorca, Julio; Rivas, Ramon

    2005-01-01

    New wireless technologies make possible the implementation of high level integration wireless devices which allow the replacement of traditional large wired monitoring devices. This kind of devices favours at-home hospitalization, reducing the affluence to sanitary assistance centers to make routine controls. This fact causes a really favourable social impact, especially for elder people, rural-zone inhabitant, chronic patients and handicapped people. Furthermore, it offers new functionalities to physicians and will reduce the sanitary cost. Among these functionalities, biomedical signals can be sent to other devices (screen, PDA, PC...) or processing centers, without restricting the patients' mobility. The aim of this project is the development and implementation of a reduced size multi-channel electrocardiograph based on IEEE 802.11, which allows wireless monitoring of patients, and the insertion of the information into the TCP/IP Hospital network.

  14. CERN Technical Training 2003: Learning for the LHC! MAGNE-03 : Magnétisme pour l'Electrotechnique Phénomènes magnétiques, matériaux et applications - French version only

    CERN Multimedia

    2003-01-01

    MAGNE-03 est un nouveau cours dans le cadre du programme de l'Enseignement Technique 2003, qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Recommandé par l'ancienne division LHC, le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France, 38). La participation est ouverte à l'ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. En ayant organisé des sessions au CERN, une économie d'environ 800.- CHF par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur leur site en Isère. MAGNE-03 s'intéresse, entre autres, au développement de la compréhension des phénomènes magnétiques et le "sens physique" appliqués à des produits industriels. Programme : Notions de base en électromagnétisme. Les aspects électrique et mécanique du magnétisme. Les ...

  15. CERN Technical Training 2003: Learning for the LHC! MAGNE-03 : Magnétisme pour l'Electrotechnique
    Phénomènes magnétiques, matériaux et applications. - French version only

    CERN Multimedia

    2003-01-01

    MAGNE-03 est un nouveau cours dans le cadre du programme de l'Enseignement Technique 2003, qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Recommandé par l'ancienne division LHC, le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France, 38). La participation est ouverte à l'ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. En ayant organisé des sessions au CERN, une économie d'environ 800.- CHF par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur leur site en Isère. MAGNE-03 s'intéresse, entre autres, au développement de la compréhension des phénomènes magnétiques et le "sens physique" appliqués à des produits industriels. Programme : Notions de base en électromagnétisme. Les aspects électrique et mécanique du magnétisme. Les ...

  16. IEEE International Workshop on Machine Learning for Signal Processing: Preface

    DEFF Research Database (Denmark)

    Tao, Jianhua

    The 21st IEEE International Workshop on Machine Learning for Signal Processing will be held in Beijing, China, on September 18–21, 2011. The workshop series is the major annual technical event of the IEEE Signal Processing Society's Technical Committee on Machine Learning for Signal Processing...

  17. Applications magnétoélectriques des supraconducteurs

    CERN Document Server

    Mangin, Philippe

    2018-01-01

    La supraconductivité est devenue incontournable, par exemple avec l’IRM qui équipe nos hôpitaux. Elle permet de spectaculaires réalisations tels le LHC du CERN qui a mis en évidence le boson de Higgs, le projet de fusion nucléaire ITER, le train à sustentation magnétique, etc. Ces applications dans divers domaines reposent sur l’aptitude des fils supraconducteurs à transporter de très fortes intensités de courant et sur l’énorme champ magnétique que des bobines supraconductrices peuvent créer. Elles sont l’objet du présent ouvrage avec d’abord l’élaboration des fils supraconducteurs, prouesse technologique tant pour les câbles Nb – Ti et Nb3Sn que pour les rubans de cuprates. Ensuite, pour chaque application, sont présentés les phénomènes physiques et le fonctionnement des dispositifs technologiques ; le lecteur peut ainsi acquérir une vision globale des apports scientifiques de ces technologies et de leurs enjeux, scientifiques, médicaux et sociétaux. Trois autres ouvrag...

  18. Applications magnétoélectriques des supraconducteurs

    CERN Document Server

    Mangin, Philippe

    2018-01-01

    La supraconductivité est devenue incontournable, par exemple avec l’IRM qui équipe nos hôpitaux. Elle permet de spectaculaires réalisations tels le LHC du CERN qui a mis en évidence le boson de Higgs, le projet de fusion nucléaire ITER, le train à sustentation magnétique, etc. Ces applications dans divers domaines reposent sur l’aptitude des fils supraconducteurs à transporter de très fortes intensités de courant et sur l’énorme champ magnétique que des bobines supraconductrices peuvent créer. Elles sont l’objet du présent ouvrage avec d’abord l’élaboration des fils supraconducteurs, prouesse technologique tant pour les câbles Nb – Ti et Nb$_{3}$Sn que pour les rubans de cuprates. Ensuite, pour chaque application, sont présentés les phénomènes physiques et le fonctionnement des dispositifs technologiques ; le lecteur peut ainsi acquérir une vision globale des apports scientifiques de ces technologies et de leurs enjeux, scientifiques, médicaux et sociétaux. Trois autres o...

  19. Facts about trans fats

    Science.gov (United States)

    Trans fat is a type of dietary fat . Of all the fats, trans fat is the worst for your health. Too much ... from solid margarine to soft margarine. Ask what type of fats foods are cooked in when you eat out ...

  20. Trans as Contested Intelligibility

    DEFF Research Database (Denmark)

    Raun, Tobias

    2014-01-01

    Denne artikel rejser en række epistemologiske og metodologiske spørgsmål vedrørende læsningen af trans som identitetskategori. Disse spørgsmål er stærkt underbelyste i en skandinavisk akademisk kontekst, om end der el- lers i stigende grad produceres analyser af trans identitetsnarrativer. Artikl...

  1. Proceedings of IEEE Machine Learning for Signal Processing Workshop XV

    DEFF Research Database (Denmark)

    Larsen, Jan

    These proceedings contains refereed papers presented at the Fifteenth IEEE Workshop on Machine Learning for Signal Processing (MLSP’2005), held in Mystic, Connecticut, USA, September 28-30, 2005. This is a continuation of the IEEE Workshops on Neural Networks for Signal Processing (NNSP) organized...... by the NNSP Technical Committee of the IEEE Signal Processing Society. The name of the Technical Committee, hence of the Workshop, was changed to Machine Learning for Signal Processing in September 2003 to better reflect the areas represented by the Technical Committee. The conference is organized...... by the Machine Learning for Signal Processing Technical Committee with sponsorship of the IEEE Signal Processing Society. Following the practice started two years ago, the bound volume of the proceedings is going to be published by IEEE following the Workshop, and we are pleased to offer to conference attendees...

  2. Performance comparison of IEEE 802.11g and IEEE 802.11n in the presence of interference from 802.15.4 networks

    OpenAIRE

    Masood, Syed Haani

    2013-01-01

    In this paper we compare the packet error rate (PER) and maximum throughput of IEEE 802.11n and IEEE 802.11g under interference from IEEE 802.15.4 by using MATLAB to simulate the IEEE PHY for 802.11n and 802.11g networks.

  3. A coexistence model of IEEE 802.15.4 and IEEE 802.1 lbIg

    NARCIS (Netherlands)

    Yuan, Wei; Wang, Xiangyu; Linnartz, J.P.M.G.

    2007-01-01

    IEEE 802.15.4 was developed to meet the needs for low-rate wireless communication. However, due to its low power, IEEE 802.15.4 is potentially vulnerable to interference by other wireless technologies having much higher power and working in the same industrial, scientific, and medical (ISM) band

  4. Principios termodinámicos de la refrigeración magnética

    OpenAIRE

    JOHN HOYOS; FARID CHEJNE; CÉSAR CHAVES; JUAN VELÁSQUEZ; ALAN HILL

    2006-01-01

    La Refrigeración magnética es una de las tecnologías con mayor potencial comercial debido a sus ventajas ambientales y energéticas frente a los sistemas convencionales. Este artículo presenta los aspectos termodinámicos más importantes del efecto magnetocalórico, fundamental en el estudio de las transformaciones magnéticas y el desarrollo de la refrigeración magnética. También se explican los ciclos magnéticos de Carnot, Brayton y de Regeneración Magnética Activa aplicados a la refrigeración ...

  5. Active Channel Reservation for Coexistence Mechanism (ACROS) for IEEE 802.15.4 and IEEE 802.11

    Science.gov (United States)

    Shin, Soo Young; Woo, Dong Hyuk; Lee, Jong Wook; Park, Hong Seong; Kwon, Wook Hyun

    In this paper, a coexistence mechanism between IEEE 802.15.4 and IEEE 802.11b, Active Channel Reservation for cOexiStence (ACROS), is proposed. The key idea underlining ACROS is to reserve the channel for IEEE 802.15.4 transmission, where IEEE 802.11 transmissions are forbidden. The request-to-send (RTS)/clear-to send (CTS) mechanism within IEEE 802.11 is used to reserve a channel. The proposed ACROS mechanism is implemented into a PC based prototype. The embedded version of ACROS is also developed to mitigate the timing drift problem in the PC-based ACROS. The efficiency of ACROS is shown using the throughput and packet error rate achieved in actual experiments.

  6. CERN Technical Training 2003: Learning for the LHC !
    MAGNE-03 : MagnEtisme pour l'Electrotechnique
    Phénomènes magnétiques, matériaux et applications - French version only

    CERN Multimedia

    2003-01-01

    MAGNE-03 est un cours dans le cadre du programme de l'Enseignement technique 2003 qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l'ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. En ayant organisé des sessions au CERN, une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur leur site en Isère. MAGNE-03 s'intéresse, entre autres, au développement de la compréhension des phénomènes magnétiques et le «&...

  7. Iconografía por Resonancia Magnética

    Directory of Open Access Journals (Sweden)

    Jaime Gómez Gonzalez

    1987-04-01

    Full Text Available

    Iconografía, del griego “eikon” imagen y “graphein” dibujar, es la ciencia de las imágenes. La reproducción de imágenes del cuerpo humano puede hacerse por muchos medios, el más reciente, la Resonancia Magnética. Se trata de un procedimiento bien conocido por los químicos desde hace casi cuatro decenios y que se emplea para el análisis espectrográfico de cualquier substancia.

    Hace menos de diez años Raymond Damadian pudo utilizar este sistema para producir imágenes de cortes tomográficos del cuerpo humano en cualquier plano, sin utilizar radiaciones ionizantes. El perfeccionamiento del equipo ha llegado en los últimos tres años a producir imágenes con detalles anatómicos de gran perfección. Existe la posibilidad de hacer análisis espectrográfico en vivo, pero este procedimiento se encuentra aún en investigación.

    Para evaluar el sistema, el autor ha visitado varias fábricas en Europa y Estados Unidos, un número importante de laboratorios de centros hospitalarios en Nueva York, Houston, La Florida, y contribuyó a organizar en la Fundación Instituto Neurológico de Colombia, en colaboración con el Centro Internacional de Física, el I Seminario Internacional sobre Iconografía por Resonancia Magnética en abril de 1986, con participación de conferenciantes de Alemania, Bélgica, Dinamarca y los Estados Unidos.

    Se han compilado los informes de unos quince fabricantes, cuatro de ellos con representación en Colombia; se solicitaron cotizaciones, se realizaron estudios económicos y se consultó con arquitectos para adecuar el sitio donde se podría instalar el equipo en la Fundación Instituto Neuro lógico de Colombia, como un servicio más a la comunidad. En este momento se programa para 1987, el 11Seminario Internacional de Iconografía por Resonancia Magnética.

    El principio utilizado para obtener estas imágenes se basa en conceptos físicos muy complejos; sin embargo, se pueden

  8. Cis By Trans

    OpenAIRE

    Rodovalho,Amara Moira

    2017-01-01

    Cis, trans: above all, metaphors. Cisjordan, region skirting the Jordan River. Cisplatin, Uruguay’s ancient name, region occupying one of the banks of the Prata River. Trans- Amazonian, that which crosses the Amazon; transatlantic, that which crosses the Atlantic. Cisalpine, transalpine. The geometric isomerism of Organic Chemistry, where “cis” are atoms that, when molecules are divided in half, remain on the same side, and “trans” those remaining on opposite sides. Ev...

  9. Guest editors' introduction : Highlights from IEEE Pacific Visualization

    NARCIS (Netherlands)

    Wijk, van J.J.; North, S.; Shen, H.-W.

    2010-01-01

    This article looks briefly at four articles based on papers from the 2010 IEEE Pacific Visualization Symposium. These articles, which strongly focus on visual design and applications, cover a range of applications in scientific visualization, information visualization, and graph visualization,

  10. IEEE Conference Record - Abstracts. 1997 IEEE International Conference on Plasma Science, 19 - 22 May 1997 San Diego, California

    National Research Council Canada - National Science Library

    Hyman, Julius

    1997-01-01

    This 360 page softbound publication includes the following major sections. An invitation to ICOPS'97, Catamaran Resort Hotel Floor Pinas, Officers of the IEEE Nuclear and Plasma Sciences Society, Conference Information...

  11. Delay Analysis of GTS Bridging between IEEE 802.15.4 and IEEE 802.11 Networks for Healthcare Applications

    Science.gov (United States)

    Mišić, Jelena; (Sherman) Shen, Xuemin

    2009-01-01

    We consider interconnection of IEEE 802.15.4 beacon-enabled network cluster with IEEE 802.11b network. This scenario is important in healthcare applications where IEEE 802.15.4 nodes comprise patient's body area network (BAN) and are involved in sensing some health-related data. BAN nodes have very short communication range in order to avoid harming patient's health and save energy. Sensed data needs to be transmitted to an access point in the ward room using wireless technology with higher transmission range and rate such as IEEE 802.11b. We model the interconnected network where IEEE 802.15.4-based BAN operates in guaranteed time slot (GTS) mode, and IEEE 802.11b part of the bridge conveys GTS superframe to the 802.11b access point. We then analyze the network delays. Performance analysis is performed using EKG traffic from continuous telemetry, and we discuss the delays of communication due the increasing number of patients. PMID:19107184

  12. Delay Analysis of GTS Bridging between IEEE 802.15.4 and IEEE 802.11 Networks for Healthcare Applications.

    Science.gov (United States)

    Misić, Jelena; Sherman Shen, Xuemin

    2009-01-01

    We consider interconnection of IEEE 802.15.4 beacon-enabled network cluster with IEEE 802.11b network. This scenario is important in healthcare applications where IEEE 802.15.4 nodes comprise patient's body area network (BAN) and are involved in sensing some health-related data. BAN nodes have very short communication range in order to avoid harming patient's health and save energy. Sensed data needs to be transmitted to an access point in the ward room using wireless technology with higher transmission range and rate such as IEEE 802.11b. We model the interconnected network where IEEE 802.15.4-based BAN operates in guaranteed time slot (GTS) mode, and IEEE 802.11b part of the bridge conveys GTS superframe to the 802.11b access point. We then analyze the network delays. Performance analysis is performed using EKG traffic from continuous telemetry, and we discuss the delays of communication due the increasing number of patients.

  13. Simulasi Kinerja Jaringan Nirkabel IEEE-802.11a dan IEEE-802.11g Menggunakan NS-2

    Directory of Open Access Journals (Sweden)

    Helm Fitriawan

    2014-03-01

    Full Text Available Wireless network uses transmission media based on radio waves. This type of networks is mainly useddue to its efficiency and mobility in data exchanging. This paper reports the modeling and simulation of wirelessnetworks based on Cisco Aironet 1130ag access point devices with IEEE 802.11a and IEEE 802.11g standards. Themodeling and simulation are performed using network simulator version 2 (NS-2 that is installed on operationsystem Linux Ubuntu v.10.10. The NS-2 is commonly used and works well in numerous types of network simulation. From simulation, we obtain quality of service parameters by employing several simulation scenarios in terms ofnumber of nodes, distances, and packet data sizes. It can be concluded from simulation results that the IEEE 802.11gnetworks transfer data with better quality than those of IEEE 802.11a networks.  Furthermore, the IEEE 802.11gnetworks provide a higher throughput, with smaller amount of delay and packet loss percentage compared to thoseof IEEE 802.11a networks.

  14. Magnéli oxides as promising n-type thermoelectrics

    Directory of Open Access Journals (Sweden)

    Gregor Kieslich

    2014-10-01

    Full Text Available The discovery of a large thermopower in cobalt oxides in 1997 lead to a surge of interest in oxides for thermoelectric application. Whereas conversion efficiencies of p-type oxides can compete with non-oxide materials, n-type oxides show significantly lower thermoelectric performances. In this context so-called Magnéli oxides have recently gained attention as promising n-type thermoelectrics. A combination of crystallographic shear and intrinsic disorder lead to relatively low thermal conductivities and metallic-like electrical conductivities in Magnéli oxides. Current peak-zT values of 0.3 around 1100 K for titanium and tungsten Magnéli oxides are encouraging for future research. Here, we put Magnéli oxides into context of n-type oxide thermoelectrics and give a perspective where future research can bring us.

  15. IEEE Std 101-1987: IEEE guide for the statistical analysis of thermal life test data

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This revision of IEEE Std 101-1972 describes statistical analyses for data from thermally accelerated aging tests. It explains the basis and use of statistical calculations for an engineer or scientist. Accelerated test procedures usually call for a number of specimens to be aged at each of several temperatures appreciably above normal operating temperatures. High temperatures are chosen to produce specimen failures (according to specified failure criteria) in typically one week to one year. The test objective is to determine the dependence of median life on temperature from the data, and to estimate, by extrapolation, the median life to be expected at service temperature. This guide presents methods for analyzing such data and for comparing test data on different materials

  16. Metamateriales Magnéticos de Anillos Resonantes para Aplicaciones en Imagen Médica por Resonancia Magnética.

    OpenAIRE

    Algarín Guisado, José Miguel

    2017-01-01

    La presente memoria recoge los resultados de una investigación multidisciplinar que combina la reciente disciplina de los metamateriales electromagnéticos con la técnica de obtención de imágenes médicas mediante resonancia magnética. La resonancia magnética (RM) es una de las principales técnicas de obtención de imágenes médicas junto con la tomografía axial computerizada (TAC), la ecografía po...

  17. Magnétisme et supraconductivité

    CERN Document Server

    Lévy, Laurent-Patrick

    1997-01-01

    Cet ouvrage donne une vision moderne du magnétisme et de la supraconductivité, dont il couvre à la fois les aspects microscopiques et phénoménologiques. Les notions de base sont illustrées à l'aide de sujets de recherche actuels comme l'effet Hall quantique ou les aspects mésoscopiques de la supraconductivité. L'auteur emploie systématiquement des exemples ou des arguments très intuitifs pour donner au lecteur le sens du formalisme utilisé. Ce livre est destiné aux étudiants de maîtrise ou de 3e cycle de physique de la matière condensée, ainsi qu'aux élèves ingénieurs. Il constitue une sérieuse référence qui permettra aussi aux enseignants et chercheurs d'aborder ou d'approfondir ces domaines.

  18. Fiber optics backbone for IEEE 802.3 networks

    Science.gov (United States)

    Shani, Ron

    1990-01-01

    In the last few years the IEEE 802.3 committee has developed fiber optics inter-repeater link standard called FOIRL. This standard defines the "Fiber Optics Media Access Unit" (FOMAU) which is used to connect two IEEE 802.3 repeaters that are up to 1Km apart. The IEEE 802.3 lOBaseF task force is currently standardizing a full F/O system in two directions: passive and active. The active approach is a compromise between the FOIRL (Asynchronous) approach and the Synchronous approach. As a result of this activity the IEEE 802.3 standard will define three different F/O interfaces and several devices that will not inter-operate. Such a standard will lower the credibility among the IEEE 802.3 user community, as customers will be confused amidst the many chapters and devices with no clear choice. This paper describes a method that can reduce the number of standards to two (passive and active), while proposing a solution for all the requirements of 802.3 F/O LAN. (The question of passive vs active approach will be discussed in this paper).

  19. Trans-Spatial Utopias

    Science.gov (United States)

    Kramsch, Claire

    2018-01-01

    The "trans-" perspectives offered in this special issue are heady stuff. Post-structuralism (philosophy) meets the digital age (electronics), meets globalization (economics), and meets translingual practice (linguistics) to create a perfectly utopian or placeless space for future exploration. I want to first add my voice to the…

  20. Low Trans Hydrogenation

    Science.gov (United States)

    Although hydrogenation has been the technology of choice for fat formulation for many years recent concerns over the health and nutrition of trans fatty acids have had a profound effect on the edible oil industry. Since Jan. 1, 2006, TFA has been required on nutrition labels along with saturated an...

  1. Implicit Block ACK Scheme for IEEE 802.11 WLANs

    Science.gov (United States)

    Sthapit, Pranesh; Pyun, Jae-Young

    2016-01-01

    The throughput of IEEE 802.11 standard is significantly bounded by the associated Medium Access Control (MAC) overhead. Because of the overhead, an upper limit exists for throughput, which is bounded, including situations where data rates are extremely high. Therefore, an overhead reduction is necessary to achieve higher throughput. The IEEE 802.11e amendment introduced the block ACK mechanism, to reduce the number of control messages in MAC. Although the block ACK scheme greatly reduces overhead, further improvements are possible. In this letter, we propose an implicit block ACK method that further reduces the overhead associated with IEEE 802.11e’s block ACK scheme. The mathematical analysis results are presented for both the original protocol and the proposed scheme. A performance improvement of greater than 10% was achieved with the proposed implementation.

  2. IEEE guide for the analysis of human reliability

    International Nuclear Information System (INIS)

    Dougherty, E.M. Jr.

    1987-01-01

    The Institute of Electrical and Electronics Engineers (IEEE) working group 7.4 of the Human Factors and Control Facilities Subcommittee of the Nuclear Power Engineering Committee (NPEC) has released its fifth draft of a Guide for General Principles of Human Action Reliability Analysis for Nuclear Power Generating Stations, for approval of NPEC. A guide is the least mandating in the IEEE hierarchy of standards. The purpose is to enhance the performance of an human reliability analysis (HRA) as a part of a probabilistic risk assessment (PRA), to assure reproducible results, and to standardize documentation. The guide does not recommend or even discuss specific techniques, which are too rapidly evolving today. Considerable maturation in the analysis of human reliability in a PRA context has taken place in recent years. The IEEE guide on this subject is an initial step toward bringing HRA out of the research and development arena into the toolbox of standard engineering practices

  3. IEEE prize awarded to CERN PhD student

    CERN Multimedia

    2006-01-01

    Rafael Ballabriga Suñe is the recipient of the 2006 Institute of Electrical and Electronics Engineers, Inc. (IEEE) Nuclear and Plasma Sciences Society (NPSS)'s Student Paper Award. Ballabriga's winning paper reported on a prototype chip, which belongs to a new generation of single photon counting hybrid pixel detector readout chips - Medipix3. The award was presented by the deputy programme chair Vince Cianciolo (left) at the IEEE Nuclear Science Symposium held in San Diego on 29 October to 4 November.

  4. Resonancia magnética funcional Functional magnetic resonance

    Directory of Open Access Journals (Sweden)

    Erick Sell

    2007-01-01

    Full Text Available La resonancia magnética funcional (RMNf es un estudio no invasivo de mapeo funcional cerebral, cuya señal obtenida en secuencias T2* es dependiente del nivel de oxigenación sanguínea (BOLD. Este estudio se agrega actualmente a otros muchos empleados en el abordaje de pacientes candidatos a cirugía de epilepsia, para localizar lenguaje y función motriz previa a planear la cirugía. Tiene una concordancia con el test de WADA de cerca del 90%. El uso concomitante de registro encefalográfico y RMNf es técnicamente difícil, pero una vez filtrados los artefactos presenta un patrón de activación significativamente discordante con el foco de actividad interictal. Este hallazgo podría obedecer a redes complejas de actividad epiléptica, y promete ser un útil instrumento en la investigación de la fisiopatología del tejido epileptogénico.Functional magnetic resonance imaging (fmri is a non-invasive functional brain mapping technique ased on blood oxygenated level dependent signal (BOLD. It is obtained during T2* weighted imaging MRI studies. fmri aids in the localization of language and motor function for patients candidates for epilepsy surgery, and has up to a 90% concordance with WADA test. Even though synchronous recording of fmri and EEG is technically challenging, it shows a discordant pattern of activation when compared with EEG or electrocorticography. This finding could be due to complex epileptic networks, and overall this study technique has the potential to contribute to further research into epileptic network and epilepsy physiopathology.

  5. Modèle tridimensionnel pour coupler les équations magnétiques et électriques dans le cas de la magnétostatique

    Science.gov (United States)

    Piriou, F.; Razek, A.

    1991-03-01

    In this paper a 3D model for coupling of magnetic and electric equations is presented. The magnetic equations are solved with the help of finite element method using the magnetic vector potential formulation. To take into account the effects of magnetic saturation we use the Newton-Raphson algorithm. We develop the analysis permitting the coupling of magnetic and electric equations to obtain a difrerential system equations which can be solved with numerical integration. As example we model an iron core coil and the validity of our model is verified by a comparison of the obtained results with an analytical solution and a 2D code calculation. Dans cet article est présenté un modèle 3D qui permet de coupler les équations magnétiques et électriques. Les équations magnétiques sont résolues à l'aide de la méthode des éléments finis en utilisant une formulation en potentiel vecteur magnétique. Dans le modèle proposé les effets de la saturation du circuit magnétique sont pris en compte en utilisant l'algorithme de Newton-Raphson. On montre comment relier les équations magnétiques avec celles du circuit électrique pour aboutir à un système d'équations différentielles que l'on résout avec une intégration numérique. A titre d'exemple on modélise une bobine à noyau ferromagnétique et pour montrer la validité du modèle on compare les résultats obtenus avec une solution analytique et un code de calcul 2D.

  6. IEEE C37.98-1987: IEEE standard seismic testing of relays

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This standard specifies the procedures to be used in the seismic testing of relays used in power system facilities. The standard is concerned with the determination of the seismic fragility level of relays and also gives recommendations for proof testing. The purpose of this standard is to establish procedures for determining the seismic capabilities of protective and auxiliary relays. These procedures employ what has been called fragility testing in IEEE Std 344-1987. To define the conditions for fragility testing of relays, parameters in three separate areas must be specified. In general, they are (1) the electrical settings and inputs to the relay, and other information to define its conditions during the test; (2) the change in state, deviation in operating characteristics or tolerances, or other change of performance of the relay that constitutes failure; (3) the seismic vibration environment to be imposed during the test. Since it is not possible to define the conditions for every conceivable application for all relays, those parameters, which in practice encompass the majority of applications, have been specified in this standard. When the application of the relay is other than as specified under any of (1), (2), and (3), or if it is not practical to apply existing results of fragility tests to that new application, then proof testing must be performed for that new case

  7. IEEE C37.98-1978: IEEE standard seismic testing of relays

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This standard specifies the procedures to be used in the seismic testing of relays used in power system facilities. The standard is concerned with the determination of the seismic fragility level of relays and also gives recommendations for proof testing. The purpose of this standard is to establish procedures for determining the seismic capabilities of protective and auxiliary relays. These procedures employ what has been called fragility testing in ANSI/IEEE Std 344-1975, Recommended Practices for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations. In order to define the conditions for fragility testing of relays, parameters in three separate areas must be specified. In general they are: (1) the electrical settings and inputs to the relay, and other information to define its conditions during the test; (2) the change in state, deviation in operating characteristics or tolerances, or other change of performance of the relay which constitutes failure; (3) the seismic vibration environment to be imposed during the test. Since it is not possible to define the conditions for every conceivable application for all relays, those parameters, which in practice encompass the majority of applications, have been specified in this standard. When the application of the relay is other than as specified under any of (1), (2), and (3), or if it is not practical to apply existing results of fragility tests to that new case

  8. A trans world journey

    DEFF Research Database (Denmark)

    Stender, Steen; Dyerberg, Jørn; Bysted, Anette

    2006-01-01

    to a maximum of 2% of fat content from 2004. We assessed the potential exposure of consumers to IP-TFA by analysing popular foods in Denmark, and in 25 other countries. Fifty-five servings of French fries and chicken nuggets, 87 packages of microwave popcorn, and 393 samples of biscuits....../cakes/wafers with "partially hydrogenated vegetable fat" listed high on the food label were bought between November 2004, and February 2006. The content of IP-TFA was analysed by standardized methodology. We defined a "high trans menu" as a large size serving of French fries and nuggets, 100 g of microwave popcorn, and 100 g......A high intake of industrially produced trans fatty acids (IP-TFA) is associated with increased risk of coronary heart disease (CHD), and a daily intake as low as possible is required to minimize health risks. To achieve this at the individual level in Denmark, legislation limited IP-TFA in foods...

  9. Una revisión del fenómeno de aislamiento magnético

    Directory of Open Access Journals (Sweden)

    Zósimo Arévalo Velosa

    2007-09-01

    Full Text Available Los dispositivos de alta energía son diseñados para que funcionen con campos eléctricos y magnéticos extrema-damente altos. Debido a esto, dichos dispositivos presentan fenómenos y comportamientos no lineales, como el aislamiento magnético que altera el transporte de los electrones. La no linealidad ha obligado a analizar y revisar desde el punto de vista matemático las condiciones de frontera y las soluciones del problema. El objetivo de este trabajo es exponer el tema a un nivel que facilite su difusión entre la comunidad académica no familiarizada con el mismo. Para ello, el trabajo presenta una descripción de los fenómenos que se generan cuando hay campos eléctricos y magnéticos muy altos, tomando el caso de un diodo plano al vacío, así como las ecuaciones que modelan el fenómeno de aislamiento magnético; también demuestra la existencia de las soluciones y encuentra las positivas en base a los métodos de solución superior e inferior para problemas de valor de frontera, y pro-porciona algunos ejemplos de aplicación del fenómeno de aislamiento magnético.

  10. Editorial for the IEEE Transactions on Power Electronics, January 2009

    DEFF Research Database (Denmark)

    Blaabjerg, Frede

    2009-01-01

    I am entering the fourth year as the Editor in Chief of the IEEE TRANSACTIONS ON POWER ELECTRONICS. A position like this becomes more and more important for the technical field as publishing in a peer-reviewed highly ranked journal has influence on the industrial and academic career. It is a way...

  11. ARC Researchers at IEEE 2015 Vehicle Power and Propulsion Conference

    Science.gov (United States)

    Contacts Researchers News & Events Event Calendar Annual Program Review Research Seminars Press Room Event Archives ARC Researchers at the IEEE 2015 Vehicle Power and Propulsion Conference (October 19-22 Ballroom B P-SS4-2 Comparison of SOFC and PEM Fuel Cell Hybrid Power Management Strategies for Mobile

  12. Eleanor McElwee and the Formation of IEEE PCS

    Science.gov (United States)

    Malone, Edward A.

    2015-01-01

    This article examines the historical professional project that created the Institute of Radio Engineers' Professional Group on Engineering Writing an Speech (IRE PGEWS)--now called the Institute of Electrical and Electronics Engineers' Professional Communication Society (IEEE PCS)--and recounts the group's early history in detail. It also traces…

  13. 2011 IEEE Vehicular Networking Conference (VNC): Demo Summaries

    NARCIS (Netherlands)

    Altintas, O.; Chen, W.; Heijenk, Geert; Dressler, F.; Ekici, E.; Kargl, Frank; Shigeno, H.; Dietzel, Stefan

    2011-01-01

    Foreword For the first time in its history, IEEE VNC has included this year’s demonstrations in its program. Demonstrations play an important role to expose the research community to practical aspects of research and to foster cross-fertilization among researchers both in academia and in industry.

  14. 0011-0030.Data Representation amp Computer Arithmetic6 IEEE ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; reso; 021; 01; 0011-0030.Data Representation amp Computer Arithmetic6 IEEE Standard Double Precision FormatIn.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News.

  15. Qualification test of Class 1E equipment based on IEEE323 Std 2003

    International Nuclear Information System (INIS)

    Kim, J. S.; Jung, S. C.; Kim, T. R.

    2004-01-01

    IEEE Standard for Qualifying Class 1E Equipment has been updated to 2003 edition since the issue of IEEE Std 323-1971, 1974, 1983. NRC approved the IEEE Std 323-1974 as Qualification standard of Class 1E Equipment in domestic nuclear power plant. IEEE Std 323-2003 was issued in September of 2003 and utility is waiting the approval of NRC. IEEE Std 323-2003 suggest a new qualification technique which adopts the condition monitoring. Performance of two transient during DBA test is no longer recommended in IEEE Std 323-2003. IEEE323 Std 2003 included a chapter of ''extension of Qualified life'' to make available the life extension of components during plant life extension. For the efficient control of preserving EQ in domestic nuclear power plant, IEEE323 Std 2003 is strongly recommended

  16. Estudio del efecto del filtrado en resonancia magnética de difusión

    OpenAIRE

    Rubio Álvarez, Jorge

    2015-01-01

    En el mundo de la medicina, las imágenes de resonancia magnética de difusión (dMRI) son una herramienta de diagnóstico fundamental ya que nos proporcionan la posibilidad de visualizar los sistemas de fibras nerviosas que componen la sustancia blanca del cerebro. El inconveniente de esta herramienta es que los datos de las imágenes de resonancia magnética de difusión se ven damnificados por diversas fuentes de ruido que, irremediablemente, merman la calidad de las adquisiciones. Este ruido lo ...

  17. Estudio de la respuesta magnética de nanopartículas en hidrogeles y en coloides. Efecto desmagnetizante debido a las interacciones dipolares magnéticas entre partículas : Fuerza magnética y transporte de nanopartículas magnéticas y adenovirus durante la magnetofección in vitro

    OpenAIRE

    Arciniegas Vaca, Magda Lorena

    2016-01-01

    Los hidrogeles magnéticos (o ferrogeles) con nanopartículas de magnetita en una matriz de PVA, poseen propiedades notables de absorción de agua, cambio de volumen por hidratación y por aplicación de campos, y liberación de fármacos. Estos materiales basan su respuesta en una concentración elevada de MNPs que pueden llegar a constituir del orden del 15 % de su masa. En esto contrastan con los coloides magnéticos para aplicaciones biomédicas, que poseen a lo sumo concentraciones másicas del ord...

  18. Aplicación móvil para medir campos magnéticos

    OpenAIRE

    Valdecantos Perales, Víctor; González, Manuel Á.

    2015-01-01

    Este proyecto tiene como objetivo medir el campo magnético en cualquier punto de la tierra mediante un dispositivo móvil con sistema operativo Android. Con estas medidas se quieren crear puntos sobre un mapa mundial que reflejen la intensidad y sentido del campo. Estos dispositivos cuentan con un gran número de sensores tales como sensor de proximidad, acelerómetro, temperatura, gravedad, luz... pero este proyecto se van a utilizar sólo dos de esos sensores: el acelerómetro y sensor magnético...

  19. Estenosis aórtica pura y resonancia magnética en el adulto

    OpenAIRE

    Meave-González, Aloha; Alexánderson, Erick; Hernández-González, Martha A; Siu, Silvia; Soto, Ma. Elena; Solorio, Sergio; Espínola-Zavaleta, Nilda

    2007-01-01

    Objetivos: Evaluar la utilidad de la resonancia magnética cardiovascular (RMC) para la cuantificación del área valvular aórtica en pacientes adultos con estenosis aórtica pura (EA). Método: Estudio transversal comparativo, cegado, en pacientes con estenosis aórtica, sin otra patología valvular asociada, en quienes se realizó ecocardiograma transtorácico bidimensional (ETT) y resonancia magnética. Los resultados se analizaron mediante t de Student, ji cuadrada considerando como significativos ...

  20. Reconstrução tridimensional de arcos magnéticos por tomografia

    Science.gov (United States)

    Simões, P. J. A.; Costa, J. E. R.

    2003-08-01

    Uma explosão solar é uma variação súbita do brilho que ocorre nas regiões ativas da atmosfera solar. Estas regiões são constituídas por um plasma magnetizado com intensa indução magnética e em cenários bem complexos como visto recentemente através de experimentos embarcados em satélites operando instrumentos em raios X moles e ultra-violeta distante. A energia magnética, que pode ser armazenada por um período de horas até dias em configurações magnéticas estressadas, é subitamente lançada na atmosfera solar e transferida para partículas como elétrons, prótons e núcleos pesados, que são acelerados e/ou aquecidos, produzindo radiação eletromagnética. A proposta final deste projeto é determinar as características espaciais de alta resolução da emissão e polarização girossincrotrônica de explosões solares em ambientes complexos de campos magnéticos. Os recentes resultados da emissão difusa em EUV apresentado pelos satélites TRACE e SOHO dos arcos magnéticos conectando as diferentes polaridades magnéticas sobre as regiões ativas possibilitam novas abordagens sobre o papel do campo magnético na emissão em rádio. Nesta etapa apresentamos os resultados da reconstrução da geometria tridimensional das linhas de força destes arcos utilizando técnicas tomográficas, a partir de imagens de alta resolução espacial obtidas pelo instrumento EIT (Extreme ultraviolet Imaging Telescope), além da modelagem das induções magnéticas por um campo dipolar e as densidades de partículas aceleradas. Utilizamos para a reconstrução geométrica, imagens tomadas em vários ângulos dos arcos devido à rotacão solar. Com estes resultados, daremos continuidade ao projeto, com os cálculos da transferência radiativa nos modos ordinário e extraordinário de propagação da radiação girossincrotrônica de explosões solares.

  1. Introduction to IEEE Std. 7-4.3.2 Annex D -- ''Qualification of existing commercial computers''

    International Nuclear Information System (INIS)

    Holmstrom, K.J.

    1995-01-01

    On September 15th of 1993 the IEEE standards board approved IEEE Std. 7-4.3.2-1993, IEEE Standard for Digital Computers in Safety Systems of Nuclear Power Generating Stations. This paper is an introduction to Annex D of this document which concerns the commercial grade dedication of existing computers or new non-1E computers

  2. IEEE C37.82-1987: IEEE standard for the qualification of switchgear assemblies for Class 1E applications in nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This document describes the methods and requirements for qualifying switchgear assemblies for indoor areas outside of the containment in nuclear power generating stations. These assemblies include (1) metal-enclosed low-voltage power circuit breaker switchgear assemblies, as defined in ANSI/IEEE C37.20.1-1987, (2) metal-clad switchgear assemblies, as defined in ANSI/IEEE C37.20.2-1987, (3) metal-enclosed bus, as defined in ANSI/IEEE C37.23-1987, and (4) metal-enclosed interrupter switchgear assemblies, as defined in ANSI/IEEE C37.20.3-1987. The purpose of this document is to provide amplification of the general requirements of ANSI/IEEE Std 323-1983 as they apply to the specific features of Class 1E switchgear assemblies. Where differences exist between this document and ANSI/IEEE Std 323-1983, this document takes precedence insofar as switchgear assemblies are concerned

  3. Proceedings of IEEE Machine Learning for Signal Processing Workshop XVI

    DEFF Research Database (Denmark)

    Larsen, Jan

    These proceedings contains refereed papers presented at the sixteenth IEEE Workshop on Machine Learning for Signal Processing (MLSP'2006), held in Maynooth, Co. Kildare, Ireland, September 6-8, 2006. This is a continuation of the IEEE Workshops on Neural Networks for Signal Processing (NNSP......). The name of the Technical Committee, hence of the Workshop, was changed to Machine Learning for Signal Processing in September 2003 to better reflect the areas represented by the Technical Committee. The conference is organized by the Machine Learning for Signal Processing Technical Committee...... the same standard as the printed version and facilitates the reading and searching of the papers. The field of machine learning has matured considerably in both methodology and real-world application domains and has become particularly important for solution of problems in signal processing. As reflected...

  4. IEEE prize awarded to CERN PhD student

    CERN Multimedia

    2006-01-01

    Rafael Ballabriga Suñe (right) receives the Student Paper Award. Rafael Ballabriga Suñe is the recipient of the 2006 Institute of Electrical and Electronics Engineers, Inc. (IEEE) Nuclear and Plasma Sciences Society (NPSS)'s Student Paper Award. Ballabriga's winning paper reported on a prototype chip, which belongs to a new generation of single photon counting hybrid pixel detector readout chips - Medipix3. The NPSS established this award in 2005 to encourage outstanding student contributions and greater student participation as principle or sole authors of papers. The prizes were presented at the IEEE Nuclear Science Symposium held in San Diego on 29 October to 4 November. The prototype chip was designed by Ballabriga based on ideas generated within the CERN Medipix team - part of the PH Microelectronics group. It could be used in various fields in the future, including medical imaging, neutron imaging, electron microscopy, radiation monitoring and other applications in high-energy physics. The novel aspe...

  5. IEEE 802.3 Fiber Optic Inter-Repeater Link

    Science.gov (United States)

    Tarrant, Peter J.

    1987-01-01

    This paper describes the implementation of a fiber optic inter-repeater link (FOIRL), used for connecting two remote copper segments of an IEEE 802.3 local area network. The rationale for the design, the signalling used and the collision detection mechanism is discussed. The evolution of the draft international standard for the FOIRL and the concurrence amongst various manufacturers is also presented. Finally some examples of typical applications, highlighting the ease of installation, are given.

  6. Basic security measures for IEEE 802.11 wireless networks

    OpenAIRE

    Sarmiento, Oscar P.; Guerrero, Fabio G.; Rey Argote, David

    2008-01-01

    This article presents a tutorial/discussion of three commonly-used IEEE 802.11 wireless network security standards: WEP, WPA and WPA2. A detailed analysis of the RC4 algorithm supporting WEP is presented, including its vulnerabilities. The WPA and WPA2 encryption protocols’ most relevant aspects and technical characteristics are reviewed for a comparative analysis of the three standards in terms of the security they provide. Special attention has been paid to WEP encryption by using an educat...

  7. 17th IEEE NPSS Real Time Conference – RT-2010

    CERN Multimedia

    Carlos Varandas

    2010-01-01

    Congress Centre of “Instituto Superior Técnico”, Lisboa, Portugal, 24-28 May, 2010 ABSTRACT SUBMISSION OPEN Abstract Submission Deadline: March 1st, 2010 Dear Sir/Madam, We are pleased to announce that abstract submission for the 17th IEEE NPSS Real Time Conference is now open on our web site. The deadline for submitting an abstract is 1st March 2010. Full conference details General Chairman

  8. Registro multimodal de mamografías: resonancia magnética y rayos-x.

    OpenAIRE

    Solves Llorens, Juan Antonio

    2014-01-01

    Solves Llorens, JA. (2014). Registro multimodal de mamografías: resonancia magnética y rayos-x [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/38940. Alfresco

  9. Sistema de medición, control y compensación activa para ciclado de campo magnético en aplicaciones de resonancia magnética nuclear

    OpenAIRE

    Forte, Guillermo Omar

    2013-01-01

    Tesis (DCI)--FCEFN-UNC, 2013 Analiza aspectos de la instrumentación asociada a la técnica de Resonancia Magnética Nuclear (RMN) con Ciclado Rápido de Campo Magnético (FFC, por sus siglas en inglés), los que afectan directamente la calidad de las mediciones realizadas. Se implementó un método para la corrección estática de la dependencia espacial del campo magnético generado por el electroimán principal del sistema, dentro de un volúmen determinado.

  10. Proceedings IEEE Visualization Conference and IEEE Information Visualization Conference (VIS'07 and INFOVIS'07, Sacramento CA, USA, October 28-November 1, 2007)

    NARCIS (Netherlands)

    Chen, M.; Hansen, C.; North, C.; Pang, A.; Wijk, van J.J.

    2007-01-01

    These are the proceedings of the IEEE Visualization Conference 2007 (Vis 2007) and the IEEE Information Visualization Conference 2007 (InfoVis 2007) held during October 28 to November 1, 2007 in Sacramento, California. The power of using computing technology to create useful, effective imagery for

  11. Coexistence of IEEE 802.11b/g WLANs and IEEE 802.15.4 WSNs : Modeling and Protocol Enhancements

    NARCIS (Netherlands)

    Yuan, W.

    2011-01-01

    As an emerging short-range wireless technology, IEEE 802.15.4/ZigBee Wireless Sensor Networks (WSNs) are increasingly used in the fields of home control, industrial control, consumer electronics, energy management, building automation, telecom services, personal healthcare, etc. IEEE

  12. Radical feminists & trans activists truce

    OpenAIRE

    Mackay, F.

    2014-01-01

    #GenderWeek: Truce! When radical feminists and trans feminists empathise\\ud Feminist Times\\ud By Finn Mackay \\ud read all #GenderWeek articles.\\ud We wanted to explore the ground between the polarised, entrenched positions in the so-called “TERF-war”. Radical feminists on one pole, trans-inclusionary feminists and trans activists on the other. The disputed territory being women-only space, language and the ever changing legal framework surrounding gender.\\ud Entrenchment leads to stalemate. S...

  13. 15th IEEE International Conference on Intelligent Engineering Systems

    CERN Document Server

    Živčák, Jozef; Aspects of Computational Intelligence Theory and Applications

    2013-01-01

    This volume covers the state-of-the art of the research and development in various aspects of computational intelligence and gives some perspective directions of development. Except the traditional engineering areas that contain theoretical knowledge, applications, designs and projects, the book includes the area of use of computational intelligence in biomedical engineering. „Aspects of Computational Intelligence: Theory and Applications” is a compilation of carefully selected extended papers written on the basis of original contributions presented at the 15th IEEE International Conference on Intelligent Engineering Systems 2011, INES 2011 held at June 23.-26. 2011 in AquaCity Poprad, Slovakia.    

  14. Status of the IEEE P896 Future Backplane Bus

    International Nuclear Information System (INIS)

    Gustavson, D.B.

    1983-10-01

    The IEEE P896 Future Backplane Bus project has been influenced by and has influenced FASTBUS and several other contemporary bus designs. This paper summarizes the current status of that project, which is directed toward the needs of modern 32-bit microprocessor systems with multiple processors. Some of the technology developed for P896 will be important for future non-ECL implementations of FASTBUS and other buses. In particular, new bus drivers and receivers should greatly improve the performance and reliability of backplane buses and cable buses. The current status of the P896 serial bus is also summarized

  15. Extending Service Area of IEEE 802.11 Ad Hoc Networks

    Science.gov (United States)

    Choi, Woo-Yong

    2012-06-01

    According to the current IEEE 802.11 wireless LAN standards, IEEE 802.11 ad hoc networks have the limitation that all STAs (Stations) are in the one-hop transmission range of each other. In this paper, to alleviate the limitation of IEEE 802.11 ad hoc networks we propose the efficient method for selecting the most appropriate pseudo AP (Access Point) from among the set of ad hoc STAs and extending the service area of IEEE 802.11 ad hoc networks by the pseudo AP's relaying the internal traffic of IEEE 802.11 ad hoc networks. Numerical examples show that the proposed method significantly extends the service area of IEEE 802.11 ad hoc networks.

  16. IEEE Std 649-1991: IEEE standard for qualifying Class 1E motor control centers for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The basic principles, requirements, and methods for qualifying Class 1E motor control centers for both harsh and mild environment applications in nuclear power generating stations are described. In addition to defining specific qualification requirements for Class 1E motor control centers and their components in accordance with the more general qualification requirements of IEEE Std 323-1983, this standard is intended to provide guidance in establishing a qualification program for demonstrating the adequacy of Class 1E motor control centers in nuclear power generating station applications

  17. Mecanismos de hidratação do óxido de magnésio

    OpenAIRE

    Amaral,L. F.; Salomão,R.; Frollini,E.; Pandolfelli,V. C.

    2007-01-01

    O óxido de magnésio, MgO, é uma importante matéria-prima para a indústria de refratários por ser um material de elevada refratariedade (ponto de fusão próximo a 2800 °C), resistente a escórias básicas, e de custo competitivo. No entanto, em presença de água, o MgO rapidamente se hidrata formando hidróxido de magnésio, Mg(OH)2. Essa reação leva a uma expansão volumétrica de até três vezes, limitando sua aplicação em concretos refratários. Para desenvolver soluções que minimizem este problema, ...

  18. Campo magnético generado por N bobinas alineadas axialmente

    OpenAIRE

    César Gutiérrez Tapia; Javier González Damián

    2002-01-01

    El cálculo del campo magnético generado por n bobinas axialmente alineadas permanece como un importante problema técnico en el proceso de construcción de los diferentes dispositivos para confinar el plasma con perfiles de campo externo tipo espejo. A partir de los métodos numéricos existentes para el cálculo de las integrales elípticas de primera clase k y segunda clase e, se describe la obtención de expresiones simples para calcular el campo magnético por el método de las ecuaciones elíptica...

  19. O campo magnético e a massa dos mésons

    OpenAIRE

    Camila Sampaio Machado

    2013-01-01

    Neste trabalho buscamos explorar os efeitos do campo magnético, criado em colisões de íons pesados não-centrais, em estados ligados. Motivados pelo caso do átomo de hidrogênio, onde a presença do campo magnético deixa o estado mais ligado,estudamos o caso dos mésons B e D. Inicialmente trabalhamos com a equação de Schrödinger e utilizamos o modelo de potencial de Cornell que faz uma boa descrição da espectroscopoia de mésons pesados. Em seguida, utilizando as regras de soma da QCD, procuram...

  20. Efeitos corrosivos encontrados em materiais magnéticos empregados em ortodontia

    OpenAIRE

    Itabaiana Sobrinho, Sisenando

    2006-01-01

    O emprego de ligas magnéticas permitiu a criação de novas opções em terapias odontológicas, especialmente na Ortodontia, onde a sua utilização já é bastante difundida. A inovação no emprego dos magnetos veio com a introdução de novas ligas magnéticas à base dos elementos terras raras pertencentes à família dos lantanídeos, como as ligas de samário-cobalto (SmCo5) e neodímio-ferro-boro (Nd2Fe14B). Magnetos fabricados com as ligas acima são 20 vezes mais fortes que os magnetos de alumínio-níque...

  1. Modelado y control de un sistema de levitación magnética basado en un cojinete magnético activo

    Directory of Open Access Journals (Sweden)

    Marlon Cruz Pegueros

    2017-01-01

    Full Text Available En este trabajo se presenta el diseño, modelado e implementación de un sistema de levitación magnética de un grado de libertad, que consiste en una viga actua da por un cojine te magnético activo en configuración pendular. Se obt iene su representación en espacio de estado y, tras una linealización tangente, su función de transferencia correspondiente. Se describen las características del dispositivo experimental, su instrumentación electrónica y mecanismo, particularmente el proce dimiento de diseño del actuador electromagnético empleado, así como su caracterización para determinar la constante de proporc ionalidad de la fuerza electromagné tica. Finalmente, se muestra la simulación numérica e implementación experimental de esquemas c lásicos de control para estabilizar en el punto de equilibrio del sistema.

  2. IEEE Standard for qualification of Class 1E lead storage batteries for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    This document describes qualification methods for Class 1E lead storage batteries and racks to be used in nuclear power generating stations outside of primary containment. Qualification required in ANSI/IEEE Std 279-1979 and IEEE Std 308-1978, can be demonstrated by using the procedures provided in this Standard in accordance with IEEE Std 323-1974. Battery sizing, maintenance, capacity testing, installation, charging equipment and consideration of other types batteries are beyond the scope of this Standard

  3. IEEE standard for qualification of class 1E lead storage batteries for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    IEEE Std 323-1974, Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations, was developed to provide guidance for demonstrating and documenting the adequacy of electrical equipment used in all Class 1E and interface systems. This standard, IEEE Std 535-1979, was developed to provide specific methods and type test procedures for lead storage batteries in reference to IEEE Std 323-1974

  4. Resonancia magnética nuclear en la evaluación de la hipertensión pulmonar

    OpenAIRE

    Caroli, Christian; aman, Bettina; Embón, Mario; Cohen Arazi, Hernán; Perrone, Sergio V.

    2009-01-01

    Se presentan las imágenes de resonancia magnética nuclear de una paciente de 38 años portadora de hipertensión pulmonar idiopática. We present the images of nuclear magnetic resonance of a 38-year-old woman with idiopathic pulmonary hypertension. Apresentam-se as imagens de ressonância magnética nuclear de uma paciente de 38 anos portadora de hipertensão pulmonar idiopatica.

  5. Propriedades magnéticas de organismos magnetotácticos: um trabalho multidisciplinar

    OpenAIRE

    Margato,Bianca; Santos,Maylla dos; Barros,Henrique Lins de

    2007-01-01

    Medidas do momento magnético de microorganismos magnetotácticos foram realizadas a partir do estudo de movimento de células no meio aquoso. Essas medidas fornecem informações importantes para a compreensão de processos adaptativos dos seres vivos. O presente trabalho oferece uma técnica que pode ser aplicada no ensino de física, biologia ou ecologia e é um exemplo de pesquisa multidisciplinar.

  6. Un visco-densimetro de flotación magnética

    Directory of Open Access Journals (Sweden)

    Jorge Alejo Pinzón B.

    2010-07-01

    Full Text Available Tomando como referencia un viscosímetro de Ubbelohde se diseñó y construyó una celda para la medida conjunta de la viscosidad y la densidad, por el método de flotación magnética, de una solución. En esta celda se pueden generar soluciones de concentraciones diferentes mediante la dilución de una solución concentrada.

  7. Efeitos neurotóxicos de sulfato de magnésio intratecal

    Directory of Open Access Journals (Sweden)

    Levent Ozdogan

    2013-02-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Avaliar os potenciais efeitos neurotóxicos em nível ultraestrutural desulfato de magnésio administrado por via intratecal em dose única ou múltipla. MÉTODOS: Estudo realizado com 24 ratos Sprague-Dawley, peso médio entre 250 e 300 g. Apósjejum de 4 horas, os ratos receberam 10 mg.kg-1 de cloreto de xilazina por via intraperitoneale, em seguida, foram divididos aleatoriamente em três grupos. Grupo I (n = 8 recebeu 0,9% desoro fisiológico normal, Grupo II (n = 8 recebeu uma injeção de 0,02 mL de sulfato de magnésioa 15% por via intratecal e Grupo III (n = 8 recebeu 0,02 mL de sulfato de magnésio a 15% umavez por dia durante sete dias. As injeções foram aplicadas dentro de 0,40x50 milímetros daárea lombar. Após sete dias, os animais foram sacrificados sob anestesia com uma injeção deformaldeído a 10% na aorta e os tecidos foram fixados. A medula espinal foi, então, examinadae histopatologicamente avaliada sob microscópio eletrônico. O teste de Kruskal-Wallis foi usadopara avaliação estatística. Um valor de p < 0,05 foi considerado estatisticamente significativo. RESULTADOS: Neurodegeneração significativa foi detectada nos ratos que receberam uma únicainjeção ou injeções repetidas de sulfato de magnésio, em comparação com o grupo controle. O escore na avaliação histopatológica desse grupo também foi alto. CONCLUSÃO: Com base no exame de microscopia eletrônica, descobrimos que a administraçãointratecal de sulfato de magnésio induziu neurodegeneração.

  8. Proceedings of the IEEE Machine Learning for Signal Processing XVII

    DEFF Research Database (Denmark)

    The seventeenth of a series of workshops sponsored by the IEEE Signal Processing Society and organized by the Machine Learning for Signal Processing Technical Committee (MLSP-TC). The field of machine learning has matured considerably in both methodology and real-world application domains and has...... become particularly important for solution of problems in signal processing. As reflected in this collection, machine learning for signal processing combines many ideas from adaptive signal/image processing, learning theory and models, and statistics in order to solve complex real-world signal processing......, and two papers from the winners of the Data Analysis Competition. The program included papers in the following areas: genomic signal processing, pattern recognition and classification, image and video processing, blind signal processing, models, learning algorithms, and applications of machine learning...

  9. Editorial for IEEE Transactions on Power Electronics, January 2013

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Lehman, Brad

    2013-01-01

    should increase the impact factor of the IEEE TRANSACTIONS ON POWER ELECTRONICS (TPEL). In 2007, TPEL published 2600 pages, and it has gradually been increased to 4000 pages in 2011, 5000 pages in 2012, and 5500 pages are projected for 2013. We have decided to publish 12 printed issues so every month...... a new issue will be printed. A graph is provided showing the number of regular papers received in the past years as well as the number of published pages in the TPEL. Finally they note that in 2008, TPEL obtained a record high value for the impact factor (as shown in a figure) but in 2009 it was reduced...... the papers to be read over a longer time span; 2) Web of Science (ISI Thomsen Reuter) began to register new power electronics conferences in their database, and citations from conferences counts and contributes to a higher impact factor....

  10. Report of the 2017 IEEE Cyber Science and Technology Congress

    Directory of Open Access Journals (Sweden)

    Wenbing Zhao

    2017-12-01

    Full Text Available The modern digitized world has led to the emergence of a new paradigm on global information networks and infrastructures known as Cyberspace and the studies of Cybernetics, which bring seamless integration of physical, social and mental spaces. Cyberspace is becoming an integral part of our daily life from learning and entertainment to business and cultural activities. As expected, this whole concept of Cybernetics brings new challenges that need to be tackled. The 2017 IEEE Cyber Science and Technology Congress (CyberSciTech 2017 provided a forum for researchers to report their research findings and exchange ideas. The congress took place in Orlando, Florida, USA during 6–10 November 2017. Not counting poster papers, the congress accepted over fifty papers that are divided into nine sessions. In this report, we provide an overview of the research contributions of the papers in CyberSciTech 2017.

  11. WIH-based IEEE 802.11 ECG monitoring implementation.

    Science.gov (United States)

    Moein, A; Pouladian, M

    2007-01-01

    New wireless technologies make possible the implementation of high level integration wireless devices which allow the replacement of traditional large wired monitoring devices. It offers new functionalities to physicians and will reduce the costs. Among these functionalities, biomedical signals can be sent to other devices (PDA, PC . . . ) or processing centers, without restricting the patients' mobility. This article discusses the WIH (Ward-In-Hand) structure and the software required for its implementation before an operational example is presented with its results. The aim of this project is the development and implementation of a reduced size electrocardiograph based on IEEE 802.11 with high speed and more accuracy, which allows wireless monitoring of patients, and the insertion of the information into the Wi-Fi hospital networks.

  12. Basic security measures for IEEE 802.11 wireless networks

    Directory of Open Access Journals (Sweden)

    Oscar P. Sarmiento

    2008-05-01

    Full Text Available This article presents a tutorial/discussion of three commonly-used IEEE 802.11 wireless network security standards: WEP, WPA and WPA2. A detailed analysis of the RC4 algorithm supporting WEP is presented, including its vulnera-bilities. The WPA and WPA2 encryption protocols’ most relevant aspects and technical characteristics are reviewed for a comparative analysis of the three standards in terms of the security they provide. Special attention has been paid to WEP encryption by using an educational simulation tool written in C++ Builder for facilitating the unders-tanding of this protocol at academic level. Two practical cases of wireless security configurations using Cisco net-working equipment are also presented: configuring and enabling WPA-Personal and WPA2-Personal (these being security options used by TKIP and AES, respectively.

  13. IEEE Std 535-1979: IEEE standard for qualification of Class 1E lead storage batteries for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This document describes qualification methods for Class 1E lead storage batteries and racks to be used in nuclear power generating stations outside of primary containment. Qualification required in ANSI/IEEE Std 279-1971 and IEE Std 308-1978, can be demonstrated by using the procedures provided in this standard in accordance with IEEE Std 323-1974. Battery sizing, maintenance, capacity testing, installation, charging equipment and consideration of other type batteries are beyond the scope of this standard

  14. IEEE Std 535-1986: IEEE standard for qualification of Class 1E lead storage batteries for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This document describes qualification methods for Class 1E lead storage batteries and racks to be used in nuclear power generating stations outside of primary containment. Qualification required in ANSI/IEEE Std 308-1980 can be demonstrated by using the procedures provided in this standard in accordance with ANSI/IEEE Std 323-1983. Battery sizing, maintenance, capacity testing, installation, charging equipment, and consideration of other type batteries are beyond the scope of this standard

  15. IEEE Std 650-1990: IEEE standard for qualification of Class 1E static battery chargers and inverters for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Methods for qualifying static battery chargers and inverters for Class 1E installations in a mild environment outside containment in nuclear power generating stations are described. The qualification methods set forth employ a combination of type testing and analysis, the latter including a justification of methods, theories, and assumptions used. These procedures meet the requirements of IEEE Std 323-1983, IEEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations

  16. A formal analysis of ISO/IEEE P11073-20601 standard of medical device communication

    NARCIS (Netherlands)

    Goga, Nicolae; Costache, Stefania; Moldoveanu, Florica

    2009-01-01

    This article presents the formal work done for the ISO/IEEE P11073-20601 Draft Standard for Health informatics - Personal health device communication - Application profile Optimized exchange protocol. ISO/IEEE 11073 family defines standards for device communication between agents (e.g. blood

  17. Comparison Of Several Methods Of Implementing A Fiber Optic IEEE 802.3 Ethernet

    Science.gov (United States)

    Thompson, Geoffrey O.

    1987-01-01

    Several different methods of implementing a fiber optic version of IEEE 802.3 10BASE LANs have been proposed as a candidate for standardization by IEEE. There have been extensive discussions as to the relative merits and features of the several systems. This paper will discuss the merits of each for this particular application on a comparative basis.

  18. 0011-0030.How to make an abstract in IEEE Format for ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; reso; 021; 01; 0011-0030.How to make an abstract in IEEE Format for AvishkarMulticultural Night in IEEE R10 Student Congress 2009Performances.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook ...

  19. 0011-0030.What is IEEE 754 StandardHow to convert real number ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; reso; 021; 01; 0011-0030.What is IEEE 754 StandardHow to convert real number in binary format using IEEE 754 StandardAn.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News.

  20. Comportamiento de la susceptibilidad magnética en el ambiente ofiolítico del nordeste de Cuba oriental

    Directory of Open Access Journals (Sweden)

    José A. Batista-Rodríguez

    2009-03-01

    Full Text Available Se analiza el comportamiento de la susceptibilidad magnética en las rocas de ambiente ofiolítico del nordeste de Cuba oriental con el propósito de esclarecer, en esta zona, la naturaleza geológica de las anomalías del campo magnético; para ello se consideraron, primeramente, resultados de investigaciones petrofísicas anteriores que incluyeran la susceptibilidad magnética; posteriormente, en dos etapas de muestreo separadas por un intervalo de 5 años, se midió esta propiedad en un total de 374 muestras. El estudio permitió conocer que la susceptibilidad magnética constituye un reflejo de la composición e historia geológica de las diferentes rocas de la región, e inferir variaciones en el grado de serpentinización de las rocas ultramáficas, así como el enriquecimiento en minerales magnéticos en todas las rocas estudiadas. Las peridotitas serpentinizadas y los diques de gabros presentan los valores más altos de susceptibilidad magnética reflejando, para las peridotitas, su grado de serpentinización en una relación directa. Ambos grupos de rocas son los principales responsables del comportamiento del campo magnético, el cual parece estar vinculado a las características geométricas y físicas de las peridotitas y algunos diques de gabros.

  1. Trans fatty acid isomers and the trans-9/trans-11 index in fat containing foods

    Science.gov (United States)

    Kuhnt, Katrin; Baehr, Melanie; Rohrer, Carsten; Jahreis, Gerhard

    2011-01-01

    To determine trans fatty acid (TFA) distribution of contemporary foods, especially regarding individual trans octadecenoic acids (trans C18:1), 339 German foods of six categories (semi-solid fats, deep-fried potato products, bakery products, confectioneries, instant products and butter) were analysed using two GC methods. Results showed a high variation of TFA content between and within the categories containing between 0 and 40.5% of FAME except in butter, which is a source of natural TFA. The mean TFA values were below 2.0% of FAME, however, bakery products contained 4.5% and butter fat 3.2%, respectively. In addition, the distribution of individual trans C18:1 differed. In samples containing ruminant fat (butter and various confectioneries), vaccenic acid (t11-C18:1, t11) predominated, while in foods containing industrially hydrogenated fats, elaidic acid (trans-9, t9-) and t10-C18:1 were the major trans isomers.. This was reflected by a low t9/t11 index of 0.3 and 0.5 in butter and ruminant fat containing confectioneries, respectively, whilst the highest index was observed in shortenings and deep-fried potato products at 5.2 and 6.8, respectively. In conclusion, the TFA content of foods available on the German market is generally declining, but substantial variations are present. The t9/t11 index could be used as an indicator to determine ruminant fat. Practical applications: A number of studies provide evidence that a high TFA intake, particularly of industrial origin, adversely affects human health. The TFA content of foods could be reduced due to the introduction of several mandatory regulations and modifications regarding the hydrogenation process of oils. The most abundant dietary TFA are the isomers of trans C18:1. Unfortunately, the differentiation of these isomers is not yet very common, though the trans C18:1 profile differs depending on its origin (bacterial hydrogenation in the rumen or industrial hydrogenation). To date, data for TFA content

  2. IEEE Std 323-1983: IEEE standard for qualifying Class 1E equipment for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This standard describes the basic requirements for qualifying Class 1E equipment with interfaces that are to be used in nuclear power generating stations. The requirements presented include the principles, procedures, and methods of qualification. These qualification requirements, when met, will confirm the adequacy of the equipment design under normal, abnormal, design basis event, post design basis event, and in-service test conditions for the performance of safety function(s). The purpose of this standard is to identify requirements for the qualification of Class 1E equipment, including those interfaces whose failure could adversely affect the performance of Class 1E equipment and systems. The methods described shall be used for qualifying equipment, extending qualification, and updating qualification if the equipment is modified. Other issued IEEE standards which present qualification methods for specific equipment or components, or both, and those that deal with parts of the qualification program, may be used to supplement this standard, as applicable

  3. IEEE Std 649-1980: IEEE standard for qualifying Class 1E motor control centers for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This standard describes the basic principles, requirements, and methods for qualifying Class 1E motor control centers for outside containment applications in nuclear power generating stations. Qualification of motor control centers located inside containment in a nuclear power generating station is beyond the scope of this standard. The purpose of this standard is (1) to define specific qualification requirements for Class 1E motor control centers in accordance with the more general qualification requirements of IEEE Std 323-1974, IEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations; (2) to provide guidance in establishing a qualification program for demonstrating the design adequacy of Class 1E motor control centers in nuclear power generating station applications

  4. Performance Analysis of IEEE 802.11 DCF and IEEE 802.11e EDCA in Non-saturation Condition

    Science.gov (United States)

    Kim, Tae Ok; Kim, Kyung Jae; Choi, Bong Dae

    We analyze the MAC performance of the IEEE 802.11 DCF and 802.11e EDCA in non-saturation condition where device does not have packets to transmit sometimes. We assume that a flow is not generated while the previous flow is in service and the number of packets in a flow is geometrically distributed. In this paper, we take into account the feature of non-saturation condition in standards: possibility of transmission performed without preceding backoff procedure for the first packet arriving at the idle station. Our approach is to model a stochastic behavior of one station as a discrete time Markov chain. We obtain four performance measures: normalized channel throughput, average packet HoL (head of line) delay, expected time to complete transmission of a flow and packet loss probability. Our results can be used for admission control to find the optimal number of stations with some constraints on these measures.

  5. Attacks on IEEE 802.11 wireless networks

    Directory of Open Access Journals (Sweden)

    Dejan Milan Tepšić

    2013-06-01

    Full Text Available Security of wireless computer networks was initially secured with the WEP security protocol, which relies on the RC4 encryption algorithm and the CRC algorithm to check the integrity. The basic problems of the WEP are a short initialization vector, unsafe data integrity checking, using a common key, the lack of mechanisms for management and exchange of keys, the lack of protection from the endless insertion of the same package into the network, the lack of authentication of access points and the like. The consequences of these failures are easy attacks against the WEP network, namely their complete insecurity. Therefore, the work began on the IEEE 802.11i protocol, which should radically improve the security of wireless networks. Since the development of a protocol lasted, the WPA standard was released to offset the security gap caused by the WEP. The WPA also relies on RC4 and CRC algorithms, but brings temporary keys and the MIC algorithm for data integrity. The 802.1X authentication was introduced and common keys are no longer needed, since it is possible to use an authentication server. The length of the initialization vector was increased and the vector is obtained based on the packet serial number, in order to prevent the insertion of the same packet into the network. The weakness of the WPA security mechanism is the use of a common key. WPA2 (802.11i later appeared. Unlike the WPA mechanism that worked on old devices with the replacement of software, WPA2 requires new network devices that can perform AES encryption. AES replaces the RC4 algorithm and delivers much greater security. Data integrity is protected by encryption. Despite progress, there are still weaknesses in wireless networks. Attacks for denial of service are possible as well as spoofing package headers attacks. For now, it is not advisable to use wireless networks in environments where unreliability and unavailability are not tolerated. Introduction In the entire history of

  6. Producción de frío a partir de campos magnéticos. Parte 2: Análisis termodinámico

    OpenAIRE

    Juan Esteban Velásquez; Farid Chejne; Alan F. J. Hill

    2003-01-01

    En la refrigeración magnética se emplea un material magnético, el cual experimenta cambios de temperatura o intercambios de calor con los alrededores cuando se somete a un campo magnético intenso. En este artículo se analiza un ciclo convencional de refrigeración magnética. Se obtienen expresiones para el calor liberado y absorbido y los cambios de temperaturas en las diferentes etapas del ciclo partiendo de la primera ley de la termodinámica. Así mismo, con el empleo de la ...

  7. CERN Technical Training 2003: Learning for the LHC ! MAGNE-03 : MAGNETISME POUR L'ELECTROTECHNIQUE - French version only

    CERN Multimedia

    Monique Duval

    2003-01-01

    Phénomènes magnétiques, matériaux et applications MAGNE-03 est un cours dans le cadre du programme de l'Enseignement technique 2003 qui s'adresse aux personnes souhaitant découvrir, améliorer ou remettre à niveau leurs connaissances en magnétisme. Le cours est donné au CERN par la société CEDRAT Technologies basée à Meylan (France). La participation est ouverte à l'ensemble du personnel technique et scientifique nécessitant une formation en magnétisme dans le cadre de leurs activités professionnelles, courantes ou futures. En ayant organisé des sessions au CERN, une importante économie par participant est réalisée par rapport aux frais nécessaires pour suivre la même formation sur leur site en Isère. MAGNE-03 s'intéresse, entre autres, au développement de la compr&am...

  8. La imagen por resonancia magnética en el estudio de la esquizofrenia

    OpenAIRE

    Salgado Pineda, Pilar; Vendrell, Pere

    2004-01-01

    La resonancia magnética ha tenido una amplia aplicación en el ámbito de la esquizofrenia para investigar sus bases neuroanatómicas y funcionales. Los estudios estructurales han evolucionado desde las mediciones semiautomáticas de estructuras aisladas hasta las sofisticadas técnicas de análisis automático vóxel a vóxel, denominadas voxel-based morphometry. Actualmente, existen hallazgos consientes y confluentes sobre la existencia de diversas anomalías estructur...

  9. Medidas de efecto hall y resistividad en aleaciones magnéticas amorfas basadas en cofe

    OpenAIRE

    Melo-Quintero, Jhon; Rosales-Rivera, Andrés; Giraldo-Daza, Helver

    2012-01-01

    En este trabajo, presentamos el diseño y la automatización de un sistema de medición de efecto Hall de corriente directa (DC) y corriente alterna (AC) usando un método de cuatro puntas. Este sistema consiste en una fuente de corriente directa y alterna (Modelo 6221 CD-CA, Keithley Instruments Inc.) acoplada a un nano-voltímetro (Modelo 2182 A, Keithley Instruments Inc.), y un electroimán (Phylatex) que proporciona campos magnéticos de hasta 0,8 T. Este sistema tiene varias capacidades de medi...

  10. Jaume Gil, orguener valencià del temps del Magnànim.

    OpenAIRE

    Cortés Escrivà, Josepa

    1985-01-01

    Peripècia vital i professional de Jaume Gil (+València 1444), constructor d’orgues, que treballà en diverses ocasions per al rei Alfons el Magnànim fabricant alguns orgues destinats a la capella reial. S’inclou, així mateix, edició de l’inventari post mortem dels seus béns, entre ells alguns instruments musicals i vuit llibres de gramàtica, i les eines del seu ofici. Vital and professional vicissitudes of Jaume Gil (+Valencia 1444), organs builder, which worked on several occasions to King...

  11. La resonancia magnética en el diagnóstico de la sialoadenosis parotidea

    OpenAIRE

    Paz, J.; Velasco-Ortega, Eugenio

    1997-01-01

    La resonancia magnética (RM) constituye una técnica exploratoria importante en el diagnóstico de la patología de cabeza y cuello. Recientemente, se ha incorporado al estudio de las glándula salivales, espcialmente la parótida. En el presente trabajo se presentan los hallazgos por RM en siete casos de sialoadenosis parotidea. Las imágenes por RM demuestran el agrandamiento glandular uni o bilateral, el incremento en el tamaño de las lesiones y el diagnóstico de los cambios en la estructura int...

  12. Estudio mediante resonancia magnética de efectos pretransicionales en cristales líquidos

    OpenAIRE

    Vaca Chavez, Fabián

    2002-01-01

    Tesis (Doctor en Física)--Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física, 2002. Se presenta el estudio mediante la técnica de Resonancia Magnética Nuclear de los efectos pretransicionales en diferentes fases de cristales líquidos termotrópicos y liotrópicos. Estos compuestos son materia de innumerables trabajos tanto teóricos como experimentales, debido a que son materiales extremadamente interesantes por sus aplicaciones tecnológicas, ópticas y biológicas. Se...

  13. Campo magnético discontinuo en adultos con hipertensión arterial esencial

    OpenAIRE

    Enrique Arce Morera; Jorge Remis Sotelo; Jesús Hernández Méndez; Ismael Castañeda Rodríguez

    2003-01-01

    Se realizó un estudio piloto a 44 casos remitidos al Departamento de Fisioterapia de nuestro municipio con diagnóstico de hipertensión arterial esencial ligera y moderada, aplicándosele 15 sesiones de campo magnético discontinuo durante 15 min. Para buscar el grado de efectividad se utilizó el método estadístico de Mc Nemar, resultando muy significativa la reducción en los valores de la presión arterial, principalmente la máxima. Hubo un favorable efecto socioeconómico, pues se ahorró en el e...

  14. Resonancia magnética cardiaca: medidas lineales y volumétricas en adultos sanos

    OpenAIRE

    Heredia Sánchez, Fabian Mauricio; Cabezas, Andrés Mauricio

    2015-01-01

    Introducción: La gran mayoría de las medidas de normalidad utilizadas para la interpretación de resonancia cardiaca son extrapoladas de las medidas de ecocardiografía. Los limitados registros de medidas de normalidad se encuentran ajustados en poblaciones extranjeras, no hay registros en latinoamericanos. Objetivo: Determinar las dimensiones cardiacas utilizando resonancia magnética en una población de personas sin antecedente médicos con repercusión cardiaca para lograr una muestra de val...

  15. IEEE Std 730 Software Quality Assurance: Supporting CMMI-DEV v1.3, Product and Process Quality Assurance

    Science.gov (United States)

    2011-05-27

    frameworks 4 CMMI-DEV IEEE / ISO / IEC 15288 / 12207 Quality Assurance ©2011 Walz IEEE Life Cycle Processes & Artifacts • Systems Life Cycle Processes...TAG to ISO TC 176 Quality Management • Quality: ASQ, work experience • Software: three books, consulting, work experience • Systems: Telecom & DoD...and IEEE 730 SQA need to align. The P730 IEEE standards working group has expanded the scope of the SQA process standard to align with IS 12207

  16. Integration of Heterogeneous Bibliographic Information through Data Abstractions.

    Science.gov (United States)

    1986-01-01

    11-12 [COMPENDEX] a) Electronics v 56 n 7 Apr 7 1983 p 155-157. b) IEEE Trans Magn v Mag-14 n 5 Sep 1978, INTERMAG (lnt Magn) Conf, I Florence, Italy ...developed a g0eograph.Cally distributed information systems as DOE/ PECaN . DOD/OROLS. NASA/RECON. CAS On-Line. OARC (France) and DECHEMA (West Germany

  17. IEEE 802.11ah: A Technology to Face the IoT Challenge.

    Science.gov (United States)

    Baños-Gonzalez, Victor; Afaqui, M Shahwaiz; Lopez-Aguilera, Elena; Garcia-Villegas, Eduard

    2016-11-22

    Since the conception of the Internet of things (IoT), a large number of promising applications and technologies have been developed, which will change different aspects in our daily life. This paper explores the key characteristics of the forthcoming IEEE 802.11ah specification. This future IEEE 802.11 standard aims to amend the IEEE 802.11 legacy specification to support IoT requirements. We present a thorough evaluation of the foregoing amendment in comparison to the most notable IEEE 802.11 standards. In addition, we expose the capabilities of future IEEE 802.11ah in supporting different IoT applications. Also, we provide a brief overview of the technology contenders that are competing to cover the IoT communications framework. Numerical results are presented showing how the future IEEE 802.11ah specification offers the features required by IoT communications, thus putting forward IEEE 802.11ah as a technology to cater the needs of the Internet of Things paradigm.

  18. 48 CFR 52.223-16 - IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false IEEE 1680 Standard for the... CONTRACT CLAUSES Text of Provisions and Clauses 52.223-16 IEEE 1680 Standard for the Environmental Assessment of Personal Computer Products. As prescribed in 23.706(b)(1), insert the following clause: IEEE...

  19. An Asynchronous IEEE Floating-Point Arithmetic Unit

    Directory of Open Access Journals (Sweden)

    Joel R. Noche

    2007-12-01

    Full Text Available An asynchronous floating-point arithmetic unit is designed and tested at the transistor level usingCadence software. It uses CMOS (complementary metal oxide semiconductor and DCVS (differentialcascode voltage switch logic in a 0.35 µm process using a 3.3 V supply voltage, with dual-rail data andsingle-rail control signals using four-phase handshaking.Using 17,085 transistors, the unit handles single-precision (32-bit addition/subtraction, multiplication,division, and remainder using the IEEE 754-1985 Standard for Binary Floating-Point Arithmetic, withrounding and other operations to be handled by separate hardware or software. Division and remainderare done using a restoring subtractive algorithm; multiplication uses an additive algorithm. Exceptionsare noted by flags (and not trap handlers and the output is in single-precision.Previous work on asynchronous floating-point arithmetic units have mostly focused on single operationssuch as division. This is the first work to the authors' knowledge that can perform floating-point addition,multiplication, division, and remainder using a common datapath.

  20. Refrigeración magnética: análisis del modelo de electrones localizados

    OpenAIRE

    John Jairo Hoyos Quintero; Juan Esteban Velásquez; Farid Chejne; Alan Hill

    2005-01-01

    La refrigeración magnética es una de las tecnologías con mayor potencial comercial. Reduce el consumo de energía en los sistemas de refrigeración y el impacto ambiental provocado por los gases de invernadero. En este artículo se presentan los aspectos fundamentales del efecto magnetocalórico. También se analiza la aplicación real del modelo de electrones localizados a la refrigeración magnética. En la vecindad de la temperatura de transformación magnética, el modelo sólo sirve para desc...

  1. Evidencia y neurociencias cognitivas: El caso de la resonancia magnética funcional

    Directory of Open Access Journals (Sweden)

    A. Nicolás Venturelli

    2015-12-01

    Full Text Available La resonancia magnética funcional es una de las técnicas de neuroimagen más difundidas en las neurociencias cognitivas. Su influencia tuvo un rol importante en la configuración del costado experimental de este campo. Frente a esto, consideramos que su estatus como evidencia no sido suficientemente discutido en la literatura filosófica. Aquí nos centramos sobre este punto desde la óptica de la tensión clásica sobre el alcance de los enfoques localizacionistas en neurociencias. Atendemos al modo en que esta tensión se manifiesta hoy. Tomamos en cuenta un número de limitaciones que presenta la resonancia magnética funcional y analizamos el modo en que los investigadores les hacen frente. En función de esto, sostenemos que existe una medida importante en que la técnica puede ser orientada sobre la base de supuestos y consideraciones teóricas generales. Para sustentar nuestras ideas, tomamos algunos ejemplos recientes de abordajes neurocientíficos caracterizados por abordar de manera directa el carácer dinámico de la actividad a gran escala en el cerebro.

  2. Augmenting the Energy-Saving Impact of IEEE 802.3az via the Control Plane

    OpenAIRE

    Thaenchaikun , Chakadkit; Jakllari , Gentian; Paillassa , Béatrice

    2015-01-01

    International audience; IEEE 802.3az, the recent standard for Energy Efficient Ethernet, is one of the main contributions of the ICT industry to the global quest for energy efficiency. Energy consumption reduction is accomplished by essentially replacing the continuous IDLE of legacy IEEE 802.3 cards with a Low Power Idle. While this is an important step in the right direction, studies have shown that the energy saving with IEEE 802.3az highly depends on the traffic load and stops for link ut...

  3. Energy Harvesting - Wireless Sensor Networks for Indoors Applications Using IEEE 802.11

    DEFF Research Database (Denmark)

    Fafoutis, Xenofon; Sørensen, Thomas; Madsen, Jan

    2014-01-01

    The paper investigates the feasibility of using IEEE 802.11 in energy harvesting low-power sensing applications. The investigation is based on a prototype carbon dioxide sensor node that is powered by artificial indoors light. The wireless communication module of the sensor node is based on the RTX......4100 module. RTX4100 incorporates a wireless protocol that duty-cycles the radio while being compatible with IEEE 802.11 access points. The presented experiments demonstrate sustainable operation but indicate a trade-off between the benefits of using IEEE 802.11 in energy harvesting applications...

  4. Estudio del Efecto de Campos Magnéticos en Citoesqueleto de Osteoblastos Humanos Estudio del Efecto de Campos Magnéticos en Citoesqueleto de Osteoblastos Humanos

    Directory of Open Access Journals (Sweden)

    Modesto Sosa Aquino

    2012-02-01

    Full Text Available En este trabajo se presentan los resultados obtenidos de la aplicación de Campos Magnéticos (CM tanto pulsados (CMP como estáticos (CME en la morfología de osteoblastos humanos. El efecto de dichos campos ha sido medido por medio del análisis de la estructura de la β-tubulina, la cual es una proteína que forma parte del citoesqueleto celular. El campo magnético aplicado fue de 0.65 mT en el caso del CMP y de 0.5 mT en el caso del CME. La aplicación de los CM provoca alteración en el patrón de distribución normal de las redes de microtúbulos, dando lugar a la formación de agregados fluorescentes en la región cortical de la membrana celular. Las observaciones obtenidas con respecto a loscambios morfológicos de los osteoblastos, indican claramente que éstos son sensibles a la estimulación con CM, alterando su actividad celular a través de cambios en la estructuradel citoesqueleto celular.In this work are presented the results obtained from the application of magnetic fields (MF, both pulsed (PMF and static (SMF, on the morphology of human osteoblasts. The effectof such fields has been evaluated through the analysis of the structure of the β-tubuline, which is protein that forms part of the cellular cytoskeleton. The applied fields were 0.65 m Tand 0.5 mT for PMF and SMF, respectively. The application of the MF produces alterations in the pattern of normal distribution of microtubules, which gives rise to the formation of fluorescent aggregates in the cortical region of the cellular membrane. The obtained results with respect to the morphological changes in the osteoblasts clearly suggest that these are sensitive to stimulation with MFs, which alter its cellular activity through changes in cytoskeletal structures.

  5. Propiedades estructurales y magnéticas de nanopartículas de Co2Au10

    OpenAIRE

    García Mayo, Sara

    2017-01-01

    Hemos llevado a cabo una búsqueda del estado fundamental de la nanoaleación Co2Au10, que hemos comprobado que puede ser vista como un dímero de Co recubierto por diez átomos de Au, con vistas a encontrar un bit magnético estable en el límite de la miniaturización, y hemos estudiado sus propiedades estructurales y magnéticas desde una aproximación relativista escalar. Los cálculos se han realizado empleando el código VASP (Vienna Ab initio Simulation Package), que es una impleme...

  6. Performance Analysis of IEEE 802.11e (EDCF) and IEEE 802.11(DCF) WLAN Incorporating Different Physical Layer Standards

    Science.gov (United States)

    Sharma, V.; Singh, H.; Malhotra, J.

    2012-12-01

    Medium access coordination function basically implements the distributed coordination function (DCF) which provides support to best effort services but limited to QoS services. Subsequently, a new standard, namely enhanced distributed channel access (EDCA) is reported. The IEEE 802.11e (EDCA) defines MAC procedures to support QoS requirements which specifies distributed contention based access scheme to access the shared wireless media. This paper evaluates the performance of EDCA based IEEE 802.11 WLAN for various access categories (ACs) using OPNET™ Modeller 14.5. Further, the computed results are compared with DCF protocols in terms of QoS parameters. Furthermore, the simulative observation is reported at data rate of 54 Mbps using different physical layer protocols such as IEEE 802.11a/b/g to stumble on the best one to be implemented with EDCF to achieve improved QoS.

  7. Analysis of Adaptive Control Scheme in IEEE 802.11 and IEEE 802.11e Wireless LANs

    Science.gov (United States)

    Lee, Bih-Hwang; Lai, Hui-Cheng

    In order to achieve the prioritized quality of service (QoS) guarantee, the IEEE 802.11e EDCAF (the enhanced distributed channel access function) provides the distinguished services by configuring the different QoS parameters to different access categories (ACs). An admission control scheme is needed to maximize the utilization of wireless channel. Most of papers study throughput improvement by solving the complicated multidimensional Markov-chain model. In this paper, we introduce a back-off model to study the transmission probability of the different arbitration interframe space number (AIFSN) and the minimum contention window size (CWmin). We propose an adaptive control scheme (ACS) to dynamically update AIFSN and CWmin based on the periodical monitoring of current channel status and QoS requirements to achieve the specific service differentiation at access points (AP). This paper provides an effective tuning mechanism for improving QoS in WLAN. Analytical and simulation results show that the proposed scheme outperforms the basic EDCAF in terms of throughput and service differentiation especially at high collision rate.

  8. Producción de frío a partir de campos magnéticos. Parte 2: Análisis termodinámico

    Directory of Open Access Journals (Sweden)

    Juan Esteban Velásquez

    2003-01-01

    Full Text Available En la refrigeración magnética se emplea un material magnético, el cual experimenta cambios de temperatura o intercambios de calor con los alrededores cuando se somete a un campo magnético intenso. En este artículo se analiza un ciclo convencional de refrigeración magnética. Se obtienen expresiones para el calor liberado y absorbido y los cambios de temperaturas en las diferentes etapas del ciclo partiendo de la primera ley de la termodinámica. Así mismo, con el empleo de la segunda ley de la termodinámica, se obtienen ecuaciones para el trabajo consumido, el cambio de entropía y el coeficiente ideal de operación del ciclo en función de las temperaturas y de propiedades del material magnético.

  9. IEEE 1588 Time Synchronization Board in MTCA.4 Form Factor

    Science.gov (United States)

    Jabłoński, G.; Makowski, D.; Mielczarek, A.; Orlikowski, M.; Perek, P.; Napieralski, A.; Makijarvi, P.; Simrock, S.

    2015-06-01

    Distributed data acquisition and control systems in large-scale scientific experiments, like e.g. ITER, require time synchronization with nanosecond precision. A protocol commonly used for that purpose is the Precise Timing Protocol (PTP), also known as IEEE 1588 standard. It uses the standard Ethernet signalling and protocols and allows obtaining timing accuracy of the order of tens of nanoseconds. The MTCA.4 is gradually becoming the platform of choice for building such systems. Currently there is no commercially available implementation of the PTP receiver on that platform. In this paper, we present a module in the MTCA.4 form factor supporting this standard. The module may be used as a timing receiver providing reference clocks in an MTCA.4 chassis, generating a Pulse Per Second (PPS) signal and allowing generation of triggers and timestamping of events on 8 configurable backplane lines and two front panel connectors. The module is based on the Xilinx Spartan 6 FPGA and thermally stabilized Voltage Controlled Oscillator controlled by the digital-to-analog converter. The board supports standalone operation, without the support from the host operating system, as the entire control algorithm is run on a Microblaze CPU implemented in the FPGA. The software support for the card includes the low-level API in the form of Linux driver, user-mode library, high-level API: ITER Nominal Device Support and EPICS IOC. The device has been tested in the ITER timing distribution network (TCN) with three cascaded PTP-enabled Hirschmann switches and a GPS reference clock source. An RMS synchronization accuracy, measured by direct comparison of the PPS signals, better than 20 ns has been obtained.

  10. 2011 IEEE Visualization Contest Winner: Visualizing Unsteady Vortical Behavior of a Centrifugal Pump

    KAUST Repository

    Otto, Mathias; Kuhn, Alexander; Engelke, Wito; Theisel, Holger

    2012-01-01

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall

  11. Harmonization of IEEE323 and IEC60780 standards For Environmental Qualificaiton of Electric Equipment

    International Nuclear Information System (INIS)

    Kim, Jong Seog

    2009-01-01

    IEEE323 standard has been widely used for the qualification of electric equipment in Asian pacific area while IEC6070 has been mostly used in European area. Since each plant use different standard for environmental qualification, manufacturer has to perform the qualification test twice in accordance with each standard. Problem also can be happened in the plant site when they are going to purchase equipment qualified by different qualification standard which are not used in his plant. The need of harmonization of each standard has been raised several years and it is known that some studies are in progress by IEEE committee. KEPRI has a plan of comparing EQ relative standards of IEEE, IEC and RCC in 2009. In this paper, brief comparing result between IEEE323 and IEC60780 and the proper harmonization method is introduced

  12. Defending IEEE 802.11-Based Networks Against Denial Of Service Attacks

    National Research Council Canada - National Science Library

    Tan, Boon

    2003-01-01

    The convenience of IEEE 8O2.11-based wireless access networks has led to widespread deployment in the consumer, industrial and military sectors However, this use is predicated on an implicit assumption of confidentiality...

  13. Corrections to "Connectivity-Based Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs"

    Directory of Open Access Journals (Sweden)

    Choi Woo-Yong

    2010-01-01

    Full Text Available We have found the errors in the throughput formulae presented in our paper "Connectivity-based reliable multicast MAC protocol for IEEE 802.11 wireless LANs". We provide the corrected formulae and numerical results.

  14. Return of IEEE Std 627 and its Value to Equipment Qualification Programs

    International Nuclear Information System (INIS)

    Horvath, D.A.

    2012-01-01

    IEEE Std 627 ''Design Qualification of Safety Systems Equipment Used in Nuclear Power Generating Stations'' was issued to more generically establish qualification requirements in the form of a high level umbrella document. Efforts on this standard began in late 1975 at the request of the IEEE Nuclear Standards Management Board. In 1977 a joint ASME/IEEE agreement established responsibility for qualification and quality assurance standards preparation. ASME accepted responsibility for Quality Assurance and IEEE for qualification. In accordance with that agreement, IEEE completed the generic qualification standard in 1980. This document provided high level approaches, criteria, guidance, and principles for qualification of both electrical and mechanical equipment that at that time appeared in no other industry standard. IEEE Std 627-1980 was later reaffirmed in 1996. In 1986, ASME's Board on Nuclear Codes and Standards directed its Committee on Qualification of Mechanical Equipment (QME) to develop a standard for qualifying mechanical equipment. This task was completed in several parts during the time frame from 1992 to 1994. Partly in response to this activity, IEEE Std 627 was withdrawn in 2002. Later although withdrawn, it was found that IEEE Std 627 was continuing to be used and referenced by many entities both in the US and other countries including in ASME's QME-1-2002 ''Qualification of Active Mechanical Equipment Used in Nuclear Power Plants'', US NRC's NUREG-0800 Standard Review Plan Section 3.11, at least one reactor vendor's Design Certification Document (DCD), several international licensing documents, and elsewhere. As a result, in 2007, the IEEE Standards Board authorized Working Group 2.10 of Subcommittee 2 (Qualification) of the Power and Energy Society's Nuclear Power Engineering Committee to resurrect and update IEEE Std 627-1980 (Reaff 1996). The result was the culmination IEEE Std 627 in 2010. This paper will report on the eight improvements made

  15. Defending IEEE 802.11-Based Networks Against Denial Of Service Attacks

    National Research Council Canada - National Science Library

    Tan, Boon

    2003-01-01

    ...) attacks targeting its management and media access protocols Computer simulation models have proven to be effective tools in the study of cause and effect in numerous fields This thesis involved the design and implementation of a IEEE 8O2.11-based simulation model using OMNeT++, to investigate the effects of different types of DoS attacks on a IEEE 8O2.11 network, and the effectiveness of corresponding countermeasures.

  16. Homeland Security Affairs Journal, Supplement - 2012: IEEE 2011 Conference on Technology for Homeland Security: Best Papers

    OpenAIRE

    2012-01-01

    Homeland Security Affairs is the peer-reviewed online journal of the Naval Postgraduate School Center for Homeland Defense and Security (CHDS), providing a forum to propose and debate strategies, policies, and organizational arrangements to strengthen U.S. homeland security. The instructors, participants, alumni, and partners of CHDS represent the leading subject matter experts and practitioners in the field of homeland security. IEEE Supplement 2012. Supplement: IEEE 2011 Conference on Te...

  17. Performance of the IEEE 802.3 EPON registration scheme under high load

    Science.gov (United States)

    Bhatia, Swapnil P.; Bartos, Radim

    2004-09-01

    The proposed standard for the IEEE 802.3 Ethernet Passive Optical Network includes a random delayed transmission scheme for registration of new nodes. Although the scheme performs well on low loads, our simulation demonstrates the degraded and undesirable performance of the scheme at higher loads. We propose a simple modification to the current scheme that increases its range of operation and is compatible with the IEEE draft standard. We demonstrate the improvement in performance gained without any significant increase in registration delay.

  18. Isolan - A Fibre Optic Network Conforming To IEEE 802.3 Standards

    Science.gov (United States)

    Roworth, D. A. A.; Howe, N.

    1986-10-01

    The progress of the IEEE 802.3 standard for fibre optic LANs is indicated with reference to both mixed media networks and full fibre networks. For a fibre optic network the most suitable layout is a "snowflake" topology composed of multiport repeaters and active fibre hubs. A range of components is described which enables the realisation of such a topology in conformance with the IEEE 802.3 standard.

  19. Validation of IEEE P1547.1 Interconnection Test Procedures: ASCO 7000 Soft Load Transfer System

    Energy Technology Data Exchange (ETDEWEB)

    Kroposki, B.; Englebretson, S.; Pink, C.; Daley, J.; Siciliano, R.; Hinton, D.

    2003-09-01

    This report presents the preliminary results of testing the ASCO 7000 Soft Load Transfer System according to IEEE P1547.1 procedures. The ASCO system interconnects synchronous generators with the electric power system and provides monitoring and control for the generator and grid connection through extensive protective functions. The purpose of this testing is to evaluate and give feedback on the contents of IEEE Draft Standard P1547.1 Conformance Tests Procedures for Equipment Interconnecting Distributed Resources With Electric Power Systems.

  20. Real-time-service-based Distributed Scheduling Scheme for IEEE 802.16j Networks

    OpenAIRE

    Kuo-Feng Huang; Shih-Jung Wu

    2013-01-01

    Supporting Quality of Service (QoS) guarantees for diverse multimedia services is the primary concern for IEEE802.16j networks. A scheduling scheme that satisfies the QoS requirements has become more important for wireless communications. We proposed an adaptive nontransparent-based distributed scheduling scheme (ANDS) for IEEE 802.16j networks. ANDS comprises three major components: Priority Assignment, Resource Allocation, Preserved Bandwidth Adjustment. Different service-type connections p...

  1. Enhancing MAC performance of DCF protocol for IEEE 802.11 wireless LANs

    Science.gov (United States)

    Choi, Woo-Yong

    2017-01-01

    The DCF (Distributed Coordination Function) is the basic MAC (Medium Access Control) protocol of IEEE 802.11 wireless LANs and compatible with various IEEE 802.11 PHY extensions. The performance of the DCF degrades exponentially as the number of nodes participating in the DCF transmission procedure increases. To deal with this problem, we propose a simple, however efficient modification of the DCF by which the performance of the DCF is greatly enhanced.

  2. Radio Frequency Fingerprinting Techniques Through Preamble Modification in IEEE 802.11B

    Science.gov (United States)

    2014-06-30

    4.2.1 Wald–Wolfowitz Runs Test . . . . . . . . . . . . . . . . . . . . . . 41 4.2.2 Wald–Wolfowitz Application to SXS System . . . . . . . . . . . . 42...Station SXS Signals eXploitation System USB Universal Serial Bus xiv Acronym Definition USRP Universal Software Radio Peripheral WLAN Wireless Local...Electronics Engineers (IEEE) defines standards applicable to the IEEE 802.11 protocol, however the standard does not reach the level of specificity to dictate

  3. TransForm: TransAlta 2000 annual report

    International Nuclear Information System (INIS)

    2001-01-01

    Financial information from TransAlta Corp. was presented along with a review of their operations throughout 2000 and a summary of the how the electric utility is doing in terms of power generation, independent power producers, transmission and energy marketing. The utility has changed from a regulated vertically integrated utility into one of Canada's largest non-regulated electric power generators. The utility sold its retail businesses in Alberta and New Zealand and now focuses on coal and hydro generation, gas generation, high-voltage transmission and energy marketing. The newly constructed Centralia, Washington generation facility was brought on line with 1,340 MW in May 2000, on time and on budget. This was the platform to diversify their generation into the United States. The utility reported a solid financial year with $177.9 million in earnings from continuing operations, an 83 per cent increase from 1999, driven mostly by the results of Centralia and power marketing and trading businesses. A financial loss was suffered when the Wabamum power plant in Alberta was shut down for several months to repair a boiler. The utility made excellent progress toward their goal of 15,000 megawatts by 2005 by starting with the construction of what will be one of Canada's largest cogeneration facilities at Sarnia, Ontario. TransAlta also commissioned a 360 MW cogeneration facility at Poplar Creek at Suncor's Fort McMurray oil sand facility. TransAlta also has an excellent track record in developing power generation projects internationally. refs., tabs., figs

  4. O papel da ressonância magnética na miocardiopatia dilatada

    OpenAIRE

    Beleza, Pedro Miguel Pereira

    2012-01-01

    Trabalho final de mestrado integrado em Medicina área científica de Radiologia, apresentado á Faculdade de Medicina da Universidade de Coimbra Introdução: a ecografia cardíaca é o exame mais frequentemente utilizado no diagnóstico de miocardiopatia dilatada. Novos estudos mostram que a ressonância magnética apresenta várias vantagens em relação à ecografia no diagnóstico e prognóstico da doença. Objectivos: Revisão de literatura das características imagiológicas e das vantagens diagnóst...

  5. Magnétochiralité et résonances stochastiques dans les lasers

    Science.gov (United States)

    Bonnet, C.; Bretenaker, F.; Brunel, M.; Chauvat, D.; Emile, O.; Lai, N. D.; Le Floch, A.; Ropars, G.; Ruchon, T.; Singh, K.; Thépot, J.-Y.; Vallet, M.

    2002-06-01

    Les états propres d'un laser constituent un outil de choix pour étudier les différents rôles joués par le bruit dans un système. D'une part, si on veut isoler un effet petit difficilement accessible par les méthodes classiques, ces états propres permettent de réaliser des mesures différentielles de haute précision, à condition de pouvoir éliminer les bruits mécaniques, optiques, électroniques. A titre d'exemple, nous avons utilisé les états propageant et contrapropageant d'un laser ionique en anneau pour mesurer une interaction fondamentale faible: la biréfringence magnétochirale. Cette "biréfringence" se manifeste en effet par une petite variation d'indice selon le sens de parcours de l'anneau, de l'ordre de Δ n.10^{-11}, indépendante de la polarisation. A l'opposé, les deux états propres d'un laser du type Fabry-Perot constituent un système idéal pour explorer les résonances stochastiques à deux dimensions. Les résonances stochastiques par inhibition et par rotation sont isolées en présence de bruits blancs gaussiens tant pour les bruits optiques que magnétiques. L'utilisation possible de l'émission spontanée comme bruit actif est démontrée.

  6. Mapeamento do fósforo adsorvido por meio da cor e da suscetibilidade magnética do solo

    Directory of Open Access Journals (Sweden)

    Rafael Gonçalves Peluco

    2015-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a possibilidade de se mapear o fósforo adsorvido por meio da avaliação da cor e da suscetibilidade magnética do solo. O experimento foi realizado em área de cana-de-açúcar com 380 ha, que compreendia quatro tipos de Latossolos, com diferentes texturas e fertilidades naturais. Foram coletadas 241 amostras de solo, na profundidade de 0,00-0,25 m. O índice de avermelhamento do solo foi calculado a partir dos valores de matiz, valor e croma das amostras, obtidos com espectroscopia de reflectância difusa. Foram ajustados modelos de regressão entre o fósforo adsorvido e a suscetibilidade magnética ou o índice de avermelhamento dos solos. A dependência espacial dos dados foi avaliada por meio de geoestatística. A suscetibilidade magnética correlaciona-se significativamente ao fósforo adsorvido, o que possibilita seu uso como componente de funções de pedotransferência para quantificação indireta do fósforo adsorvido ao solo. O índice de avermelhamento e a suscetibilidade magnética apresentam dependência espacial com o fósforo adsorvido. A suscetibilidade magnética e o índice de avermelhamento dos solos, avaliado pela espectroscopia de reflectância difusa, podem auxiliar no mapeamento e na identificação de áreas com diferentes potenciais de adsorção de fósforo.

  7. Synthesis through Trans-disciplinarity

    DEFF Research Database (Denmark)

    Hansen, Hanne Tine Ring

    2006-01-01

    synthesis is a requirement for creating successful ‘environmentally sustainable' architecture through the application of trans-disciplinarity, which leads to an increased awareness of the differences in decision-making as well as that of communication barriers between the different professions......When looking up the word ‘synthesis' in a dictionary, one comes across the following definition: "The combining of separate elements or substances to form a coherent whole."[1] Based on this definition one could argue that all great architectureis achieved through synthesis in one way or another...

  8. Trans issues in Liz Lochhead's 'Not Changed'

    OpenAIRE

    Kaličanin Milena M.

    2017-01-01

    The paper is divided into four sections. In the first section entitled 'Introducing and Defining Trans (Issues)', the basic terms of transgender, transvestite, and transsexual are defined by relying on Stryker's Transgender History (2008). The second part of the paper, 'Trans Studies: In-Between Feminist and Queer Theory?', places transgender studies into an academic context by referring to the theoretical framework provided by trans theorists Stryker, Stone, and Ranck who unanimously claim t...

  9. The Danish trans-fatty acids ban

    DEFF Research Database (Denmark)

    Vallgårda, Signild

    2017-01-01

    In 2003 an executive order was issued banning industrially produced trans-fatty acids above a low level in food items in Denmark. To date, only a few other countries have followed Denmark’s example. The way health consequences of trans fats were translated by the different actors enabled the crea......In 2003 an executive order was issued banning industrially produced trans-fatty acids above a low level in food items in Denmark. To date, only a few other countries have followed Denmark’s example. The way health consequences of trans fats were translated by the different actors enabled...

  10. Analysis of Magnetic Nozzles For Space Plasma Thrusters = Análisis de Toberas Magnéticas para Motores Espaciales de Plasma

    OpenAIRE

    Merino Martínez, Mario

    2013-01-01

    Esta tesis presenta un análisis teórico del funcionamiento de toberas magnéticas para la propulsión espacial por plasmas. El estudio está basado en un modelo tridimensional y bi-fluido de la expansión supersónica de un plasma caliente en un campo magnético divergente. El modelo básico es ampliado progresivamente con la inclusión de términos convectivos dominantes de electrones, el campo magnético inducido por el plasma, poblaciones electrónicas múltiples a distintas temperaturas, y la capacid...

  11. Diseño de un cojinete lineal para entornos criogénicos basado en levitación magnética pasiva

    OpenAIRE

    Castro Fernández, Víctor

    2013-01-01

    El sistema magnético compuesto por el superconductor y el imán permanente se encuentra en un entorno criogénico, esencial para poder conseguir el efecto Meissner. El imán permanente produce un campo magnético, donde cierta parte de este campo es absorbido por el superconductor, que hace posible que éste se encuentre en estado Meissner siempre y cuando no se supere un cierto límite. Tal efecto provoca que el superconductor expulse el campo magnético de su interior generando un conjunto de fuer...

  12. Tratamiento magnético como técnica estimulante de la germinación de semillas de soja

    OpenAIRE

    Carbonell Padrino, Maria Victoria; Martinez Ramirez, Elvira; Florez Garcia, Mercedes

    2013-01-01

    El campo magnético está presente en la naturaleza y afecta al reino vegetal y animal. El bioelectromagnetismo es el estudio de los efectos de los campos electromagnéticos sobre los sistemas biológicos y sus interacciones con los campos magnéticos naturales y artificiales. Estudios previos han determinado que la aplicación de campos magnéticos modifica la velocidad de germinación y el desarrollo de plantas. La soja constituye uno de los cultivos oleaginosos más importantes del mundo: en las úl...

  13. FACTS ABOUT TRANS FATTY ACIDS

    Directory of Open Access Journals (Sweden)

    Sedighe Asgary

    2010-12-01

    Full Text Available Introduction Fatty acids constitute the main class of lipids in the human diet, being found in nature mainly as glycerol esters that originate triacylglycerols. In the vegetal and animal kingdoms, fatty acids generally have cis unsaturations. In this form, the hydrogens bound to the double bond carbons are on the same side. In another possible configuration, called trans, the hydrogens are bound to un saturations, carbons on opposing sides. Fatty acids with one or more un saturations in the trans configuration are called trans fatty acids (TFAs.1-4      There are two major sources of TFA, those that come from ruminant animals and those that are industrially produced.      The majority of TFAs are found in partially hydrogenated vegetable oils, which contain 10–40% as TFA.5 Hydrogenation is based on the reaction of unsaturated fatty acids of either vegetable or marine oil in the presence of a catalyst, in general nickel. The objective is to increase the oxidative stability of oils by reduction of the concentration of more unsaturated fatty acids and changing their physical properties, thus extending their application. Hydrogenation depends mainly on oil temperature, hydrogen pressure, stirring speed, reaction time, and the catalyst type and concentration. According to the process conditions, hydrogenation is classified as either partial or total and either selective or nonselective.6 It has been estimated that dietary TFAs from partially hydrogenated oils may be responsible for between 30,000 and 100,000 premature coronary deaths per year in the United States.7      The concentration of TFA in meat and milk from ruminants (i.e., cattle, sheep, goats, etc. contain 3 to 8% of total fat.5 It is hypothesized that ruminant TFAs, or certain TFA isomers from ruminant sources, may confer some health benefits; however, since TFA from animal sources accompany saturated fatty acids (SFA, an increase in a single ruminant TFA in the diet is not

  14. IEEE 1547 and 2030 Standards for Distributed Energy Resources Interconnection and Interoperability with the Electricity Grid

    Energy Technology Data Exchange (ETDEWEB)

    Basso, T.

    2014-12-01

    Public-private partnerships have been a mainstay of the U.S. Department of Energy and the National Renewable Energy Laboratory (DOE/NREL) approach to research and development. These partnerships also include technology development that enables grid modernization and distributed energy resources (DER) advancement, especially renewable energy systems integration with the grid. Through DOE/NREL and industry support of Institute of Electrical and Electronics Engineers (IEEE) standards development, the IEEE 1547 series of standards has helped shape the way utilities and other businesses have worked together to realize increasing amounts of DER interconnected with the distribution grid. And more recently, the IEEE 2030 series of standards is helping to further realize greater implementation of communications and information technologies that provide interoperability solutions for enhanced integration of DER and loads with the grid. For these standards development partnerships, for approximately $1 of federal funding, industry partnering has contributed $5. In this report, the status update is presented for the American National Standards IEEE 1547 and IEEE 2030 series of standards. A short synopsis of the history of the 1547 standards is first presented, then the current status and future direction of the ongoing standards development activities are discussed.

  15. Trans Ova Genetics, L.C.

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Trans Ova Genetics, L.C., a business located at 2938 380th Street Sioux Center, IA 51250, for alleged violations at the Trans Ova Genetics, L.C.’s facility located in 12425

  16. Unscripting Curriculum: Toward a Critical Trans Pedagogy

    Science.gov (United States)

    Keenan, Harper Benjamin

    2017-01-01

    In this essay, Harper B. Keenan draws on his own experience as a white queer and trans educator to consider the meaning of a critical trans pedagogy. Amid dissonant narratives of equal rights and subjection, he explores how his classroom teaching is shaped by his own experience of gender conditioning as well as by the contemporary political…

  17. TransAlta: More than a utility

    International Nuclear Information System (INIS)

    Mikalson, D.A.

    1991-01-01

    TransAlta Utilities Corporation is Canada's largest privately owned utility and is also a major coal mining company. In 1989, TransAlta produced 20.9% of all coal mined in Canada. A brief history of TransAlta is presented along with TransAlta's present coal operations and plans for the next three years. An overview is presented of how TransAlta Fuel Supply is organized to utilize contracted mining operation, engineering and environmental services and in-house capabilities. Recent strategic initiatives to improve organizational efficiency and the mining operations are discussed. These range from developing a common departmental vision to modifying major mining equipment. TransAlta's proactive role in clean coal combustion such as low NOx-SOx burner, integrated combined cycle gasification, and other energy research projects is reviewed. A summary is provided of recent participation of TransAlta in environmental management initiatives. Recent successes of TransAlta's unregulated subsidiary in the development of cogeneration facilities and the future of this area of business are discussed. 8 refs., 4 figs

  18. Couplage des équations électriques et magnétiques

    Science.gov (United States)

    Lombard, P.; Meunier, G.

    1993-03-01

    The non-linear analysis of electrical devices is often limited by the complexity of the power supply. In effect, in the case of solid conductors, the voltage is required, while in the case of stranded conductors, the current must be known. These restrictions are due to the nature of the field equations. A new formulation is proposed which allows the possibility to choose the power supply and choose any kind of connection between components. Two types of “magnetic conductors” are considered: solid conductors, in which eddy current can be induced and stranded conductors without eddy current. An equation combining the magnetic potential, the current and the voltage is established for each conductor. This equation is introduced into a conventional circuit analysis method. The magnetic field and circuit equations can be solved simultaneously in the resulting system. An implicit method is used to discretize the equation in time. A NewtonRaphson linearization algorithm is used to handle problems that include materials with non linear properties. This formulation is used in the commercial program FLUX2D. To illustrate one of the many applications, an A.C. electromagnet is studied. L'analyse des dispositifs électrotechniques est souvent limitée par les sources d'alimentation. En effet, dans le cas de conducteurs massifs, la valeur de la tension est requise, alors que, dans le cas de conducteurs bobinés, le courant doit être connu. Ces restrictions sont dues à la nature des équations de champ. Une nouvelle formulation est proposée qui permet de choisir la source d'alimentation et d'autoriser tous les types de connexions entre les composants. Deux types de “conducteurs magnétiques” sont considérés : les conducteurs massifs, dans lesquels des courants de Foucault peuvent être induits et les conducteurs bobinés sans courants de Foucault. Une équation associant le potentiel vecteur magnétique, le courant et la tension est établie pour chaque type de

  19. Trans fat consumption and aggression.

    Directory of Open Access Journals (Sweden)

    Beatrice A Golomb

    Full Text Available Dietary trans fatty acids (dTFA are primarily synthetic compounds that have been introduced only recently; little is known about their behavioral effects. dTFA inhibit production of omega-3 fatty acids, which experimentally have been shown to reduce aggression. Potential behavioral effects of dTFA merit investigation. We sought to determine whether dTFA are associated with aggression/irritability. METHODOLGY/PRINICPAL FINDINGS: We capitalized on baseline dietary and behavioral assessments in an existing clinical trial to analyze the relationship of dTFA to aggression. Of 1,018 broadly sampled baseline subjects, the 945 adult men and women who brought a completed dietary survey to their baseline visit are the target of this analysis. Subjects (seen 1999-2004 were not on lipid medications, and were without LDL-cholesterol extremes, diabetes, HIV, cancer or heart disease. Outcomes assessed adverse behaviors with impact on others: Overt Aggression Scale Modified-aggression subscale (primary behavioral endpoint; Life History of Aggression; Conflict Tactics Scale; and self-rated impatience and irritability. The association of dTFA to aggression was analyzed via regression and ordinal logit, unadjusted and adjusted for potential confounders (sex, age, education, alcohol, and smoking. Additional analyses stratified on sex, age, and ethnicity, and examined the prospective association. Greater dTFA were strongly significantly associated with greater aggression, with dTFA more consistently predictive than other assessed aggression predictors. The relationship was upheld with adjustment for confounders, was preserved across sex, age, and ethnicity strata, and held cross-sectionally and prospectively.This study provides the first evidence linking dTFA with behavioral irritability and aggression. While confounding is always a concern in observational studies, factors including strength and consistency of association, biological gradient, temporality, and

  20. IEEE C37.105-1987: IEEE standard for qualifying Class 1E protective relays and auxiliaries for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This standard describes the basic principles, requirements, and methods for qualifying Class 1E protective relays and auxiliaries such as test and control switches, terminal blocks, and indicating lamps for applications in nuclear power generating stations. When properly employed it can be used to demonstrate the design adequacy of such equipment under normal, abnormal, design basis event and post design basis event conditions in accordance with ANSI/IEEE Std 323-1983. When protective relays and auxiliaries are located in areas not subject to harsh environments, environmental qualification is not required. Protective relays and auxiliaries located inside primary containment in a nuclear power generating station present special conditions beyond the scope of this document. The qualification procedure presented is generic in nature. Other methods may be used at the discretion of the qualifier, provided the basic precepts of ANSI/IEEE Std 32301983 are satisfied

  1. IEEE No. 323, IEEE trial-use standard: General guide for qualifying Class I electric equipment for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This document describes the basic requirements for the qualification of Class I electric equipment. This is equipment which is essential to the safe shutdown and isolation of the reactor or whose failure or damage could result in significant release of radioactive material. The purpose of this document is to provide guidance for demonstrating the qualifications of electrical equipment as required in the IEEE Std 279 -- Criteria for Nuclear Power Generating Station Protection Systems, and IEEE Std 308 -- Criteria for Class 1E Electric Systems for Nuclear Power Generating Stations. The qualification methods described may be used in conjunction with the Guides for qualifying specific types of equipment, (see Foreword), for updating qualification following modifications or for qualifying equipment for which no applicable Guide exists

  2. Design of handoff procedures for broadband wireless access IEEE 802.16 based networks

    Directory of Open Access Journals (Sweden)

    V. Rangel–Licea

    2008-01-01

    Full Text Available IEEE 802.16 is a protocol for fixed broad band wire less access that is currently trying to add mobility among mobile users in the standard. However, mobility adds some technical barriers that should be solved first, this is the case of HO "handoff" (change of connection between two base stations "BS" by a mobile user. In this paper, the problem of HO in IEEE 802.16 is approached try ing to maintain the quality of service (QoS of mobile users. A mechanism for changing connection during HO is pre sented. A simulation model based on OPNET MODELER1 was developed to evaluate the performance of the proposed HO mechanism. Finally, this paper demonstrates that it is possible to implement a seam less HO mech a nism over IEEE 802.16 even for users with de manding applications such as voice over IP.

  3. An Extended IEEE 118-Bus Test System With High Renewable Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Pena, Ivonne; Martinez-Anido, Carlo Brancucci; Hodge, Bri-Mathias

    2018-01-01

    This article describes a new publicly available version of the IEEE 118-bus test system, named NREL-118. The database is based on the transmission representation (buses and lines) of the IEEE 118-bus test system, with a reconfigured generation representation using three regions of the US Western Interconnection from the latest Western Electricity Coordination Council (WECC) 2024 Common Case [1]. Time-synchronous hourly load, wind, and solar time series are provided for over one year (8784 hours). The public database presented and described in this manuscript will allow researchers to model a test power system using detailed transmission, generation, load, wind, and solar data. This database includes key additional features that add to the current IEEE 118-bus test model, such as: the inclusion of 10 generation technologies with different heat rate functions, minimum stable levels and ramping rates, GHG emissions rates, regulation and contingency reserves, and hourly time series data for one full year for load, wind and solar generation.

  4. PERFORMANCE STUDY OF DISTRIBUTED COORDINATION FUNCTION OVER IEEE 802.11A PHYSICAL LAYER

    Directory of Open Access Journals (Sweden)

    S. SELVAKENEDDY

    2006-06-01

    Full Text Available IEEE 802.11a is one of the latest standards to be released by the IEEE Project 802 for wireless LANs. It has specified an additional physical layer (PHY to support higher data rates, and is termed as the orthogonal frequency division multiplexing (OFDM. In order to exploit its benefits, one of the medium access control (MAC protocols specified in the IEEE 802.11 specification is called distributed coordination function (DCF. DCF is a carrier sense multiple access with collision avoidance (CSMA/CA scheme with slotted binary exponential backoff. The frames can be transmitted using the basic access scheme or the RTS/CTS scheme in DCF. It was demonstrated previously that the RTS/CTS mechanism works well in most scenarios for the previously specified PHYs. In this work, a simple simulator is developed to verify the scalability of the RTS/CTS mechanism over OFDM PHY, which supports much higher data rates.

  5. IEEE 1451.2 based Smart sensor system using ADuc847

    Science.gov (United States)

    Sreejithlal, A.; Ajith, Jose

    IEEE 1451 standard defines a standard interface for connecting transducers to microprocessor based data acquisition systems, instrumentation systems, control and field networks. Smart transducer interface module (STIM) acts as a unit which provides signal conditioning, digitization and data packet generation functions to the transducers connected to it. This paper describes the implementation of a microcontroller based smart transducer interface module based on IEEE 1451.2 standard. The module, implemented using ADuc847 microcontroller has 2 transducer channels and is programmed using Embedded C language. The Sensor system consists of a Network Controlled Application Processor (NCAP) module which controls the Smart transducer interface module (STIM) over an IEEE1451.2-RS232 bus. The NCAP module is implemented as a software module in C# language. The hardware details, control principles involved and the software implementation for the STIM are described in detail.

  6. The scalable coherent interface, IEEE P1596, status and possible applications to data acquisition and physics

    International Nuclear Information System (INIS)

    Gustavson, D.B.

    1990-01-01

    IEEE P1596, the Scalable Coherent Interface (formerly known as SuperBus) is based on experience gained while developing Fastbus (ANSI/IEEE 960-1986, IEC 935), Futurebus (IEEE P896.x) and other modern 32-bit buses. SCI goals include a minimum bandwidth of 1 GByte/sec per processor in multiprocessor systems with thousands of processors; efficient support of a coherent distributed-cache image of distributed shared memory; support for repeaters which interface to existing or future buses; and support for inexpensive small rings as well as for general switched interconnections like Banyan, Omega, or crossbar networks. This paper presents a summary of current directions, reports the status of the work in progress, and suggests some applications in data acquisition and physics. 7 refs

  7. Application of IEEE 1588 to the real-time control system of accelerator

    International Nuclear Information System (INIS)

    Ma Mingchao; Chen Jianfeng; Shen Liren; Jiang Geyang

    2014-01-01

    Background: Time synchronization is one of the core technology of realizing the real-time control of accelerator under the distributed control system architecture. The ordinary crystal frequency deviation of IEEE 1588 causes low synchronous accuracy, which doesn't meet the needs of high precision synchronization. Purpose: This paper proposes an algorithm to improve the synchronization precision caused by the crystal frequency deviation. Methods: According to the basic principle of IEEE 1588 time synchronization, a dynamic frequency compensation (DFC) algorithm module was designed and a test platform was built to verify the feasibility and practicability of the algorithm. The influence of the synchronous cycle and delay jitter of the switch on the synchronization accuracy were analyzed. Results: Experimental results showed the great precision improvement of synchronization after using DFC algorithm. Conclusion: Low synchronous accuracy caused by the crystal frequency deviation can be improved by using DFC algorithm implemented for precision time protocol (PTP) of IEEE 1588. (authors)

  8. An analytical model for the performance analysis of concurrent transmission in IEEE 802.15.4.

    Science.gov (United States)

    Gezer, Cengiz; Zanella, Alberto; Verdone, Roberto

    2014-03-20

    Interference is a serious cause of performance degradation for IEEE802.15.4 devices. The effect of concurrent transmissions in IEEE 802.15.4 has been generally investigated by means of simulation or experimental activities. In this paper, a mathematical framework for the derivation of chip, symbol and packet error probability of a typical IEEE 802.15.4 receiver in the presence of interference is proposed. Both non-coherent and coherent demodulation schemes are considered by our model under the assumption of the absence of thermal noise. Simulation results are also added to assess the validity of the mathematical framework when the effect of thermal noise cannot be neglected. Numerical results show that the proposed analysis is in agreement with the measurement results on the literature under realistic working conditions.

  9. Throughput and delay analysis of IEEE 802.15.6-based CSMA/CA protocol.

    Science.gov (United States)

    Ullah, Sana; Chen, Min; Kwak, Kyung Sup

    2012-12-01

    The IEEE 802.15.6 is a new communication standard on Wireless Body Area Network (WBAN) that focuses on a variety of medical, Consumer Electronics (CE) and entertainment applications. In this paper, the throughput and delay performance of the IEEE 802.15.6 is presented. Numerical formulas are derived to determine the maximum throughput and minimum delay limits of the IEEE 802.15.6 for an ideal channel with no transmission errors. These limits are derived for different frequency bands and data rates. Our analysis is validated by extensive simulations using a custom C+ + simulator. Based on analytical and simulation results, useful conclusions are derived for network provisioning and packet size optimization for different applications.

  10. Tratamiento magnético sobre parámetros físicos-químicos de muestras de petróleo

    OpenAIRE

    Campos-Sofia, Melek; León-Cañet, Maida; Silveira-Font, Yadira; Moro Martínez, Alina; Falcón-Hernández, José

    2015-01-01

    En este trabajo se realizó un estudio de los parámetros físico-químicos a muestras de crudo PCNm-1400 y M-30, antes y después del tratamiento magnético; con el objetivo de evaluar el efecto de un campo magnético estático sobre dichos parámetros. Al pasar la muestra de crudo M-30 por un acondicionador magnético de 0,4550 ± 0,009 T, se logra separar hasta un 52,8 % del agua presente en la muestra. No hay evidencias de la influencia del tratamiento magnético en la viscosidad ni en el comportamie...

  11. Modélisation du champ magnétique d'un propulseur M.H.D. annulaire

    OpenAIRE

    Kom , C.; Brunet , Y.

    1995-01-01

    Pour des raisons de discrétion, les champs de fuite doivent être minimisés en propulsion M.H.D. où les champs magnétiques doivent être intenses. Le calcul du champ magnétique d'un propulseur M.H.D. naval annulaire, constitué de secteurs inducteurs supraconducteurs est représenté. Dans la zone active, hors des têtes de bobines, une formulation analytique peut être utilisée. Une méthode analytique utilisant le développemment en série de Fourier du courant est adoptée pour les industeurs cylindr...

  12. An IEEE 802.11 EDCA Model with Support for Analysing Networks with Misbehaving Nodes

    Directory of Open Access Journals (Sweden)

    Szott Szymon

    2010-01-01

    Full Text Available We present a novel model of IEEE 802.11 EDCA with support for analysing networks with misbehaving nodes. In particular, we consider backoff misbehaviour. Firstly, we verify the model by extensive simulation analysis and by comparing it to three other IEEE 802.11 models. The results show that our model behaves satisfactorily and outperforms other widely acknowledged models. Secondly, a comparison with simulation results in several scenarios with misbehaving nodes proves that our model performs correctly for these scenarios. The proposed model can, therefore, be considered as an original contribution to the area of EDCA models and backoff misbehaviour.

  13. Reactive GTS Allocation Protocol for Sporadic Events Using the IEEE 802.15.4

    Directory of Open Access Journals (Sweden)

    Mukhtar Azeem

    2014-01-01

    by the IEEE 802.15.4 standard. The proposed control protocol ensures that a given offline sporadic schedule can be adapted online in a timely manner such that the static periodic schedule has not been disturbed and the IEEE 802.15.4 standard compliance remains intact. The proposed protocol is simulated in OPNET. The simulation results are analyzed and presented in this paper to prove the correctness of the proposed protocol regarding the efficient real-time sporadic event delivery along with the periodic event propagation.

  14. Analysis Of Impact Of Various Parameters On BER Performance For IEEE 802.11b

    Directory of Open Access Journals (Sweden)

    Nilesh B. Kalani

    2015-08-01

    Full Text Available Abstract This paper discusses about IEEE 802.11b simulation model implemented using LabVIEW software and its analyses for impact on bit error rate BER for different parameters as channel type channel number data transmission rate and packet size. Audio file is being transmitted processed and analyzed using the model for various parameters. This paper gives analysis of BER verses ESN0 for various parameter like data rate packet size and communication channel for the IEEE 802.11b simulation model generated using LabVIEW. It is proved that BER can be optimized by tweaking different parameters of wireless communication system.

  15. Spectrum Hole Identification in IEEE 802.22 WRAN using Unsupervised Learning

    OpenAIRE

    V. Balaji; S. Anand; C.R. Hota; G. Raghurama

    2016-01-01

    In this paper we present a Cooperative Spectrum Sensing (CSS) algorithm for Cognitive Radios (CR) based on IEEE 802.22Wireless Regional Area Network (WRAN) standard. The core objective is to improve cooperative sensing efficiency which specifies how fast a decision can be reached in each round of cooperation (iteration) to sense an appropriate number of channels/bands (i.e. 86 channels of 7MHz bandwidth as per IEEE 802.22) within a time constraint (channel sensing time). To meet this objectiv...

  16. Self-Coexistence among IEEE 802.22 Networks: Distributed Allocation of Power and Channel

    OpenAIRE

    Sayef Azad Sakin; Md. Abdur Razzaque; Mohammad Mehedi Hassan; Atif Alamri; Nguyen H. Tran; Giancarlo Fortino

    2017-01-01

    Ensuring self-coexistence among IEEE 802.22 networks is a challenging problem owing to opportunistic access of incumbent-free radio resources by users in co-located networks. In this study, we propose a fully-distributed non-cooperative approach to ensure self-coexistence in downlink channels of IEEE 802.22 networks. We formulate the self-coexistence problem as a mixed-integer non-linear optimization problem for maximizing the network data rate, which is an NP-hard one. This work explores a s...

  17. International Conference on Grey Systems and intelligent Services (IEEE GSIS 2009)

    CERN Document Server

    Liu, Sifeng; Advances in Grey Systems Research

    2010-01-01

    This book contains contributions by some of the leading researchers in the area of grey systems theory and applications. All the papers included in this volume are selected from the contributions physically presented at the 2009 IEEE International Conference on Grey Systems and Intelligent Services, November 11 – 12, 2009, Nanjing, Jiangsu, People’s Republic of China. This event was jointly sponsored by IEEE Systems, Man, and Cybernetics Society, Natural Science Foundation of China, and Grey Systems Society of China. Additionally, Nanjing University of Aeronautics and Astronautics also invested heavily in this event with its direct and indirect financial and administrative supports.

  18. IEEE 802.11e (EDCA analysis in the presence of hidden stations

    Directory of Open Access Journals (Sweden)

    Xijie Liu

    2011-07-01

    Full Text Available The key contribution of this paper is the combined analytical analysis of both saturated and non-saturated throughput of IEEE 802.11e networks in the presence of hidden stations. This approach is an extension to earlier works by other authors which provided Markov chain analysis to the IEEE 802.11 family under various assumptions. Our approach also modifies earlier expressions for the probability that a station transmits a packet in a vulnerable period. The numerical results provide the impact of the access categories on the channel throughput. Various throughput results under different mechanisms are presented.

  19. Ressonância magnética cardiovascular em veia cava inferior interrompida não prevista

    Directory of Open Access Journals (Sweden)

    Andre Mauricio Fernandes

    2012-02-01

    Full Text Available A Veia Cava Inferior (VCI interrompida é uma anomalia rara. As anomalias da VCI são clinicamente importantes para os cardiologistas e radiologistas que pretendem intervir na cavidade cardíaca direita. Descrevemos três casos de interrupção da VCI diagnosticados por meio de estudo imaginológico de ressonância magnética cardíaca.

  20. Evaluación cardiaca con tomografía computada y resonancia magnética

    Directory of Open Access Journals (Sweden)

    H. Patricia Bitar, Dra.

    2013-01-01

    Full Text Available La tomografía computada y la resonancia magnética son métodos de imagen distintos, que con los avances tecnológicos han adquirido gran importancia en la evaluación cardiaca en los últimos 10 años. La tomografía computada usa rayos X, por lo que la radiación que emite es la mayor limitante del estudio. Tiene alta resolución espacial, lo que la hace muy útil especialmente en la evaluación de las finas y tortuosas arterias coronarias. La resonancia magnética obtiene las imágenes a partir de aplicación de campos magnéticos y pulsos de radiofrecuencia. Tiene alta resolución temporal y de contraste, por lo que es particularmente útil en la evaluación de función cardiaca, siendo el gold standard, y en la caracterización de tejidos. Permite evaluar anatomía, función, medir flujos, hacer estudios de perfusión y viabilidad miocárdica. El presente artículo tiene por objetivo caracterizar las dos modalidades de imágenes, describir sus ventajas y desventajas y analizar las indicaciones de cada método en la evaluación cardiaca.

  1. Técnica de partículas magnéticas: caso del laboratorio del CAMAN

    Directory of Open Access Journals (Sweden)

    Sonia Ruth Rincón Urbina

    2015-10-01

    Full Text Available El presente artículo presenta el procedimiento general para el empleo de la técnica de partículas magnéticas; describe de manera general las principales características del ensayo y el procedimiento de inspección a desarrollar en el laboratorio del Comando Aéreo de Mantenimiento (CAMAN de la Fuerza Aérea Colombiana. El método que se empleó en la investigación y en  el desarrollo del proyecto fue de tipo documental, con el fin de establecer las normas y reglamentaciones requeridas para la certificación de la técnica en partículas magnéticas del laboratorio de pruebas no destructivas por la autoridad Aeronáutica. Finalmente, con el análisis de los métodos se elaboró el Manual de Procedimientos de Inspección con el propósito de certificar la técnica de partículas magnéticas.

  2. Campo magnético discontinuo en adultos con hipertensión arterial esencial

    Directory of Open Access Journals (Sweden)

    Enrique Arce Morera

    2003-06-01

    Full Text Available Se realizó un estudio piloto a 44 casos remitidos al Departamento de Fisioterapia de nuestro municipio con diagnóstico de hipertensión arterial esencial ligera y moderada, aplicándosele 15 sesiones de campo magnético discontinuo durante 15 min. Para buscar el grado de efectividad se utilizó el método estadístico de Mc Nemar, resultando muy significativa la reducción en los valores de la presión arterial, principalmente la máxima. Hubo un favorable efecto socioeconómico, pues se ahorró en el empleo de medicamentos $481.32 al aplicarse esta técnica.A pilot study was made on 44 cases referred to the Department of Physiotherapy of our municipality and diagnosed with light and moderate essential blood hypertension. They were administered 15 sessions of discontinuous electromagnetic field for 15 minutes. To find the level of effectiveness, we used the McNemar´s statistical method and the reduction in blood pressure values, mainly the maximum pressure was really very significant. There was also a favorable socio-economic effect since the saving in terms of drug consumption was $481.32 after the application of this technique.

  3. Ressonância magnética na esquizofrenia: um estudo morfométrico

    Directory of Open Access Journals (Sweden)

    Castro Cláudio Campi de

    2001-01-01

    Full Text Available Trinta e três pacientes esquizofrênicos crônicos e 21 indivíduos normais foram submetidos a exames de ressonância magnética em aparelho de 1,5 T, sendo realizadas imagens ponderadas em T2 nos planos axial e coronal. Foram analisados, por métodos morfométricos semi-automáticos, os volumes intracraniano, supratentorial, infratentorial, do líquido cefalorraquiano total, ventricular e subaracnóide e do encéfalo. Foram ainda medidos os volumes do complexo amígdala-hipocampo, córtex do giro para-hipocampal, putâmen, globo pálido, lobo temporal e substâncias branca e cinzenta do lobo temporal. Foram calculados os volumes relativos dessas estruturas, corrigidos pelo volume intracraniano. As alterações mais relevantes observadas nos esquizofrênicos, em comparação com os controles, foram de redução do volume relativo do encéfalo, aumento do volume relativo do líquido cefalorraquiano ventricular, subaracnóide e total. Foi ainda observada redução do volume dos complexos amígdala-hipocampo, dos lobos temporais e da substância branca dos lobos temporais, e aumento de volume dos putâmens.

  4. Automated genomic DNA purification options in agricultural applications using MagneSil paramagnetic particles

    Science.gov (United States)

    Bitner, Rex M.; Koller, Susan C.

    2002-06-01

    The automated high throughput purification of genomic DNA form plant materials can be performed using MagneSil paramagnetic particles on the Beckman-Coulter FX, BioMek 2000, and the Tecan Genesis robot. Similar automated methods are available for DNA purifications from animal blood. These methods eliminate organic extractions, lengthy incubations and cumbersome filter plates. The DNA is suitable for applications such as PCR and RAPD analysis. Methods are described for processing traditionally difficult samples such as those containing large amounts of polyphenolics or oils, while still maintaining a high level of DNA purity. The robotic protocols have ben optimized for agricultural applications such as marker assisted breeding, seed-quality testing, and SNP discovery and scoring. In addition to high yield purification of DNA from plant samples or animal blood, the use of Promega's DNA-IQ purification system is also described. This method allows for the purification of a narrow range of DNA regardless of the amount of additional DNA that is present in the initial sample. This simultaneous Isolation and Quantification of DNA allows the DNA to be used directly in applications such as PCR, SNP analysis, and RAPD, without the need for separate quantitation of the DNA.

  5. Síndrome de la cimitarra en resonancia magnética cardiovascular

    Directory of Open Access Journals (Sweden)

    Pedro Abad

    2018-01-01

    Full Text Available El síndrome de la cimitarra es una anomalía parcial del retorno venoso pulmonar de características complejas. Está asociado a múltiples malformaciones cardiovasculares y pulmonares, y representa un diagnóstico diferencial importante en los pacientes con dilatación inexplicada de las cavidades derechas. Se expone el caso de una mujer en la cuarta década de la vida, con un cuadro clínico de dolor torácico, episodios sincopales y deterioro de su clase funcional, que por sus hallazgos en la ecocardiografía fue llevada a resonancia magnética cardíaca que mostró anomalía parcial del retorno venoso pulmonar infracardiaca, hallazgo no visualizado en la ecocardiografía, y que confirmó el diagnóstico específico de síndrome de la cimitarra.

  6. The Trans-Pacific Partnership

    Directory of Open Access Journals (Sweden)

    Voon Tania

    2016-12-01

    Full Text Available This article provides an overview of the recently concluded Trans-Pacific Partnership Agreement (TPP, a treaty the parties have described as comprehensive and ambitious, yet also representing a balance of competing interests. The article focuses on the TPP’s chapters relating to investment, services, intellectual property and regulatory coherence, each of which provides insight into the motivations that drove the conclusion of the TPP and the negotiating dynamics that determined its final content. In areas such as investment, the TPP takes a more balanced approach than many earlier agreements, providing greater safeguards for the regulatory autonomy of states while still embodying core protections for foreign investors. In relation to intellectual property and services, the TPP goes beyond earlier agreements in several key respects, such as preventing the imposition of local presence requirements for service providers or requiring longer copyright terms than those demanded by other international treaties. The TPP chapter on regulatory coherence is one of the most novel features of the treaty, as regulatory coherence is not frequently included in earlier trade agreements, demonstrating the increased focus of states on addressing regulatory barriers to trade and investment. While all of these elements of the TPP are interesting in their own right, given the number and size of the parties involved in the agreement, they also provide valuable guidance about the direction of other ongoing and future preferential trade agreement negotiations, such as the proposed Transatlantic Trade and Investment Partnership (TTIP and Trade in Services Agreement (TiSA.

  7. The tree identify protocol of IEEE 1394 in uCRL

    NARCIS (Netherlands)

    C. Shankland; M.B. van der Zwaag

    1998-01-01

    textabstractWe specify the tree identify protocol of the IEEE 1394 high performance serial multimedia bus at three different levels of detail using $mu$CRL. We use the cones and foci verification technique of Groote and Springintveld to show that the descriptions are equivalent under branching

  8. A 1-GHz charge pump PLL frequency synthesizer for IEEE 1394b PHY

    DEFF Research Database (Denmark)

    Ji, J.; Liu, H.; Li, Q.

    2012-01-01

    This paper presents an implementation of multi-rate SerDes transceiver for IEEE 1394b applications. Simple and effective pre-emphasis and equalizer circuits are used at transmitter and receiver, respectively. A phase interpolator based clock and data recovery circuit with optimized linearity is a...

  9. Energy-aware path selection metric for IEEE 802.11s wireless mesh networking

    CSIR Research Space (South Africa)

    Mhlanga, MM

    2009-01-01

    Full Text Available The IEEE 802.11s working group has commenced activities, which would lead to the development of a standard for wireless mesh networks (WMNs). The draft of 802.11s introduces a new path selection metric called airtime link metric. However...

  10. Energy-aware path selection metric for IEEE 802.11s wireless mesh networking

    CSIR Research Space (South Africa)

    Mhlanga, MM

    2009-08-01

    Full Text Available The IEEE 802.11s working group has commenced activities, which would lead to the development of a standard for wireless mesh networks (WMNs). The draft of 802.11s introduces a new path selection metric called airtime link metric. However...

  11. IEEE 8023 ethernet, current status and future prospects at the LHC

    CERN Document Server

    Dobinson, Robert W; Haas, S; Martin, B; Le Vine, M J; Saka, F

    2000-01-01

    The status of the IEEE 802.3 standard is reviewed and prospects for the future, including the new 10 Gigabit version of Ethernet, are discussed. The relevance of Ethernet for experiments at the CERN Large Hadron Collider is considered, with emphasis on on-line applications and areas which are technically challenging. 8 Refs.

  12. IEEE 802.3 Ethernet, Current Status and Future Prospects at the LHC

    CERN Document Server

    Dobinson, Robert W; Haas, S W; Martin, B; Le Vine, M J; Saka, F

    2000-01-01

    The status of the IEEE 802.3 standard is reviewed and prospects for the future, including the new 10 Gigabit version of Ethernet, are discussed. The relevance of Ethernet for experiments at the CERN Large Hadron Collider is considered, with emphasis on on-line applications and areas which are technically challenging.

  13. Performance Evaluations for IEEE 802.15.4-based IoT Smart Home Solution

    Directory of Open Access Journals (Sweden)

    Nga Dinh

    2016-09-01

    Full Text Available The Internet of Things (IoT is going to be a market-changing force for a variety of real-time applications such as e-healthcare, home automation, environmental monitoring, and industrial automation. Low power wireless communication protocols offering long lifetime and high reliability such as the IEEE 802.15.4 standard have been a key enabling technology for IoT deployments and are deployed for home automation recently. The issues of the IEEE 802.15.4 networks have moved from theory to real world deployments. The work presented herein intends to demonstrate the use of the IEEE 802.15.4 standard in recent IoT commercial products for smart home applications: the Smart Home Starter Kit. The contributions of the paper are twofold. First, the paper presents how the IEEE 802.15.4 standard is employed in Smart Home Starter Kit. In particular, network topology, network operations, and data transfer mode are investigated. Second, network performance metrics such as end-to-end (E2E delay and frame reception ratio (FRR are evaluated by experiments. In addition, the paper discusses several directions for future improvements of home automation commercial products.

  14. The IEEE-SA patent policy update under the lens of EU competition law

    NARCIS (Netherlands)

    Kanevskaia, Olia; Zingales, Nicolo

    2016-01-01

    In 2015, the Institute of Electrical and Electronics Engineers (IEEE) Standardization Association made some controversial changes to its patent policy. The changes include a recommended method of calculation of FRAND royalty rates, and a request to members holding a standard essential patent (SEP)

  15. 0011-0030.IEEE 754: 64 Bit Double Precision FloatsThis.pdf | 01 ...

    Indian Academy of Sciences (India)

    Home; public; Volumes; reso; 021; 01; 0011-0030.IEEE 754: 64 Bit Double Precision FloatsThis.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 ...

  16. Evaluation of the Effects of Hidden Node Problems in IEEE 802.15.7 Uplink Performance.

    Science.gov (United States)

    Ley-Bosch, Carlos; Alonso-González, Itziar; Sánchez-Rodríguez, David; Ramírez-Casañas, Carlos

    2016-02-06

    In the last few years, the increasing use of LEDs in illumination systems has been conducted due to the emergence of Visible Light Communication (VLC) technologies, in which data communication is performed by transmitting through the visible band of the electromagnetic spectrum. In 2011, the Institute of Electrical and Electronics Engineers (IEEE) published the IEEE 802.15.7 standard for Wireless Personal Area Networks based on VLC. Due to limitations in the coverage of the transmitted signal, wireless networks can suffer from the hidden node problems, when there are nodes in the network whose transmissions are not detected by other nodes. This problem can cause an important degradation in communications when they are made by means of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) access control method, which is used in IEEE 802.15.7 This research work evaluates the effects of the hidden node problem in the performance of the IEEE 802.15.7 standard We implement a simulator and analyze VLC performance in terms of parameters like end-to-end goodput and message loss rate. As part of this research work, a solution to the hidden node problem is proposed, based on the use of idle patterns defined in the standard. Idle patterns are sent by the network coordinator node to communicate to the other nodes that there is an ongoing transmission. The validity of the proposed solution is demonstrated with simulation results.

  17. Adaptive Radio Resource Allocation in Hierarchical QoS Scheduling for IEEE 802.16 Systems

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2007-01-01

    Future mobile communication systems such as IEEE 802.16 are expected to deliver a variety of multimedia services with diverse QoS requirements. To guarantee the QoS provision, appropriate scheduler architecture and scheduling algorithms have to be carefully designed. In this paper, we propose...

  18. Evaluation of H.264/AVC over IEEE 802.11p vehicular networks

    Science.gov (United States)

    Rozas-Ramallal, Ismael; Fernández-Caramés, Tiago M.; Dapena, Adriana; García-Naya, José Antonio

    2013-12-01

    The capacity of vehicular networks to offer non-safety services, like infotainment applications or the exchange of multimedia information between vehicles, have attracted a great deal of attention to the field of Intelligent Transport Systems (ITS). In particular, in this article we focus our attention on IEEE 802.11p which defines enhancements to IEEE 802.11 required to support ITS applications. We present an FPGA-based testbed developed to evaluate H.264/AVC (Advanced Video Coding) video transmission over vehicular networks. The testbed covers some of the most common situations in vehicle-to-vehicle and roadside-to-vehicle communications and it is highly flexible, allowing the performance evaluation of different vehicular standard configurations. We also show several experimental results to illustrate the quality obtained when H.264/AVC encoded video is transmitted over IEEE 802.11p networks. The quality is measured considering two important parameters: the percentage of recovered group of pictures and the frame quality. In order to improve performance, we propose to substitute the convolutional channel encoder used in IEEE 802.11p for a low-density parity-check code encoder. In addition, we suggest a simple strategy to decide the optimum number of iterations needed to decode each packet received.

  19. IEEE Conference Record of 1980 Fourteenth Pulse Power Modulator Symposium, 3-5 June 1980.

    Science.gov (United States)

    1980-01-01

    Capacitor Discharges, Proc IEEE 113, p. able operation on Nova we are examing alter- 1549 (1966). nate switch gas (Ar:N 2 :SF 6 ) and electrode material...VOLTTA-KILOVOLTS PLATE VO LTAM --LOVLTS Figure 8. Constant Current Curve for the X2097U Figure 11. Constant Current Curve for the X2097V at 2000 Volt

  20. Oldest Packet Drop (OPD): a Buffering Mechanism for Beaconing in IEEE 802.11p VANETs

    NARCIS (Netherlands)

    van Eenennaam, Martijn; Hendriks, Luuk; Karagiannis, Georgios; Heijenk, Geert

    2011-01-01

    The IEEE 802.11p MAC technology can be used to provide connectivity for real-time vehicle control known as Cooperative Adaptive Cruise Control. Due to the real-time nature of this system, it is paramount the delay of the received information is as small as possible. This paper researches the Oldest

  1. A Comprehensive Taxonomy and Analysis of IEEE 802.15.4 Attacks

    Directory of Open Access Journals (Sweden)

    Yasmin M. Amin

    2016-01-01

    Full Text Available The IEEE 802.15.4 standard has been established as the dominant enabling technology for Wireless Sensor Networks (WSNs. With the proliferation of security-sensitive applications involving WSNs, WSN security has become a topic of great significance. In comparison with traditional wired and wireless networks, WSNs possess additional vulnerabilities which present opportunities for attackers to launch novel and more complicated attacks against such networks. For this reason, a thorough investigation of attacks against WSNs is required. This paper provides a single unified survey that dissects all IEEE 802.15.4 PHY and MAC layer attacks known to date. While the majority of existing references investigate the motive and behavior of each attack separately, this survey classifies the attacks according to clear metrics within the paper and addresses the interrelationships and differences between the attacks following their classification. The authors’ opinions and comments regarding the placement of the attacks within the defined classifications are also provided. A comparative analysis between the classified attacks is then performed with respect to a set of defined evaluation criteria. The first half of this paper addresses attacks on the IEEE 802.15.4 PHY layer, whereas the second half of the paper addresses IEEE 802.15.4 MAC layer attacks.

  2. Interference Measurements in IEEE 802.11 Communication Links Due to Different Types of Interference Sources

    NARCIS (Netherlands)

    van Bloem, J.W.H.; Schiphorst, Roelof; Kluwer, Taco; Slump, Cornelis H.

    2012-01-01

    The number of wireless devices (smartphones, laptops, sensors) that use the 2.4 GHz ISM band is rapidly increasing. The most common communication system in this band is Wi-Fi (IEEE 802.11b/g/n). For that reason coexistence between Wi-Fi and other systems becomes more and more important. In this

  3. Proceedings of the 1988 IEEE international conference on robotics and automation. Volume 1

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    These proceedings compile the papers presented at the international conference (1988) sponsored by IEEE Council on ''Robotics and Automation''. The subjects discussed were: automation and robots of nuclear power stations; algorithms of multiprocessors; parallel processing and computer architecture; and U.S. DOE research programs on nuclear power plants

  4. Performance Analysis of Non-saturated IEEE 802.11 DCF Networks

    Science.gov (United States)

    Zhai, Linbo; Zhang, Xiaomin; Xie, Gang

    This letter presents a model with queueing theory to analyze the performance of non-saturated IEEE 802.11 DCF networks. We use the closed queueing network model and derive an approximate representation of throughput which can reveal the relationship between the throughput and the total offered load under finite traffic load conditions. The accuracy of the model is verified by extensive simulations.

  5. IEEE 802.11 Wireless LANs: Performance Analysis and Protocol Refinement

    Directory of Open Access Journals (Sweden)

    Chatzimisios P.

    2005-01-01

    Full Text Available The IEEE 802.11 protocol is emerging as a widely used standard and has become the most mature technology for wireless local area networks (WLANs. In this paper, we focus on the tuning of the IEEE 802.11 protocol parameters taking into consideration, in addition to throughput efficiency, performance metrics such as the average packet delay, the probability of a packet being discarded when it reaches the maximum retransmission limit, the average time to drop a packet, and the packet interarrival time. We present an analysis, which has been validated by simulation that is based on a Markov chain model commonly used in the literature. We further study the improvement on these performance metrics by employing suitable protocol parameters according to the specific communication needs of the IEEE 802.11 protocol for both basic access and RTS/CTS access schemes. We show that the use of a higher initial contention window size does not considerably degrade performance in small networks and performs significantly better in any other scenario. Moreover, we conclude that the combination of a lower maximum contention window size and a higher retry limit considerably improves performance. Results indicate that the appropriate adjustment of the protocol parameters enhances performance and improves the services that the IEEE 802.11 protocol provides to various communication applications.

  6. Performance characterization of the IEEE 802.11 signal transmission over a multimode fiber PON

    Science.gov (United States)

    Maksymiuk, L.; Siuzdak, J.

    2014-11-01

    In this paper there are presented measurements concerning performance analysis of the IEEE 802.11 signal distribution over multimode fiber based passive optical network. In the paper there are addressed three main sources of impairments: modal noise, frequency response fluctuation of the multimode fiber and non-linear distortion of the signal in the receiver.

  7. Multitemporal Very High Resolution From Space: Outcome of the 2016 IEEE GRSS Data Fusion Contest

    NARCIS (Netherlands)

    Mou, L.; Zhu, X.; Vakalopoulou, M.; Karantzalos, K.; Paragios, N.; Saux, Le B.; Moser, G.; Tuia, D.

    2017-01-01

    In this paper, the scientific outcomes of the 2016 Data Fusion Contest organized by the Image Analysis and Data Fusion Technical Committee of the IEEE Geoscience and Remote Sensing Society are discussed. The 2016 Contest was an open topic competition based on a multitemporal and multimodal dataset,

  8. Outdoor Long-Range WLANs : A Lesson for IEEE 802.11ah

    NARCIS (Netherlands)

    Aust, Stefan; Venkatesha Prasad, R.; Niemegeers, Ignas G M M

    2015-01-01

    Several service applications have been reported by many who proposed the use of wireless LANs (WLANs) over a wide variety of outdoor deployments. In particular, the upcoming IEEE 802.11ah WLAN protocol will enable a longer transmission range between WLAN access points (APs) and stations (STAs) up to

  9. Incorporating antenna beamswitching technique into drivers for IEEE802.11 WLAN devices

    CSIR Research Space (South Africa)

    Mofolo, M

    2015-11-23

    Full Text Available the beamswitching technique for switched parasitic array (SPA) and electronically steerable parasitic array radiator (ESPAR) antennas in the drivers for IEEE802.11 WLAN devices. The modifications of the open source drivers (ath5k and ath9k) to enable real...

  10. A versatile trigger and synchronization module with IEEE1588 capabilities and EPICS support

    International Nuclear Information System (INIS)

    Lopez, J.M.; Ruiz, M.; Borrego, J.; Arcas, G. de; Barrera, E.; Vega, J.

    2010-01-01

    Event timing and synchronization are two key aspects to improve in the implementation of distributed data acquisition (dDAQ) systems such as the ones used in fusion experiments. It is also of great importance the integration of dDAQ in control and measurement networks. This paper analyzes the applicability of the IEEE1588 and EPICS standards to solve these problems, and presents a hardware module implementation based in both of them that allow adding these functionalities to any DAQ. The IEEE1588 standard facilitates the integration of event timing and synchronization mechanisms in distributed data acquisition systems based on IEEE 803.3 (Ethernet). An optimal implementation of such system requires the use of network interface devices which include specific hardware resources devoted to the IEE1588 functionalities. Unfortunately, this is not the approach followed in most of the large number of applications available nowadays. Therefore, most solutions are based in software and use standard hardware network interfaces. This paper presents the development of a hardware module (GI2E) with IEEE1588 capabilities which includes USB, RS232, RS485 and CAN interfaces. This permits to integrate any DAQ element that uses these interfaces in dDAQ systems in an efficient and simple way. The module has been developed with Motorola's Coldfire MCF5234 processor and National Semiconductors's PHY DP83640T, providing it with the possibility to implement the PTP protocol of IEEE1588 by hardware, and therefore increasing its performance over other implementations based in software. To facilitate the integration of the dDAQ system in control and measurement networks the module includes a basic Input/Output Controller (IOC) functionality of the Experimental Physics and Industrial Control System (EPICS) architecture. The paper discusses the implementation details of this module and presents its applications in advanced dDAQ applications in the fusion community.

  11. Soporte magnético para la grabación y lectura de información, método de almacenamiento y lectura de información y su uso

    OpenAIRE

    Junquera-Pérez, Alejandro; Álvarez-Prado, L. M.; Vélez, M.; Alameda, J. M.; Martín, J. I.; Marconi, V. I.; Kolton, Alejandro B.; Rodríguez-Parrondo, Juan Manuel; Anguita, José Virgilio; Souche, Yves

    2011-01-01

    Soporte magnético para la grabación y lectura de información, método de almacenamiento y lectura de información y su uso. El soporte magnético comprende un circuito magnético definido en una lámina delgada magnética con anisotropía uniaxial y un nanocomposite constituido por una red bidimensional de nanopozos asimétricos rellenos de otro material magnético de mayor coercitividad y/o anisotropía que la lámina delgada magnética. También es objeto de la invención un método de almacenamiento y le...

  12. Formation of trans fats during food preparation.

    Science.gov (United States)

    Przybylski, Oman; Aladedunye, Felix A

    2012-01-01

    An investigation was completed to determine how typical cooking procedures used in food preparation, such as baking and stir-frying, affect trans fats formation. Canola oil was used as the main fat ingredient. Zucchini cake and gingersnap cookies were baked at 180o C and 200o C, while stir-fried chicken was prepared at 200o C and 275o C. The lipids from the food were extracted following the Folch procedure, and analyzed for trans fatty acids according to ISO official method 15304. Minimal changes were observed in the amount of trans fats during baking. Application of extreme temperatures during baking, which caused carbonization of the outer layer of products, yielded an insignificant increase in the amount of trans isomers. As with baking, stir-frying did not result in significant isomerization of the fatty acids, even when the oil was heated to 275o C and smoking heavily before the food was placed in it. Irrespective of the cooking procedure, linolenic acid was the most prone to isomerization with the highest amount of trans isomers formation. Baking and stir-frying at normal and/or extreme temperatures do not significantly affect the amounts of trans fats. Likewise, heating oil to the smoking point during stir-frying may decrease the amount of polyunsaturated fatty acids because of oxidative degradation.

  13. IEEE Std 383-1974: IEEE standard for type test of Class IE electric cables, field splices, and connections for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This standard provides direction for establishing type tests which may be used in qualifying Class 1E electric cables, field splices, and other connections for service in nuclear power generating stations. General guidelines for qualifications are given in IEEE Std 323-1974, Standard for Qualifying Class IE Electric Equipment for Nuclear Power Generating Stations. Categories of cables covered are those used for power control and instrumentation services. Though intended primarily to pertain to cable for field installation, this guide may also be used for the qualification of internal wiring of manufactured devices. This guide does not cover cables for service within the reactor vessel

  14. Estudio magnético de compuestos de nanopartículas de [gamma]-ferrita dispersas en sílice mediante el efecto faraday y su aplicación a sensores de campo magnético

    OpenAIRE

    Rosa Palacios, Gregorio

    2004-01-01

    Se ha realizado un estudio de compuestos de g-Fe2O3/SiO2 a partir de desarrollos teóricos, simulaciones computacionales y pruebas experimentales. Estos experimentos se han basado en el efecto Faraday para determinar diferentes propiedades magnéticas del conjunto de nanopartículas. En este trabajo se describen los montajes experimentales desarrollados y los resultados obtenidos, así como su adecuación tanto a la teoría como a las simulaciones computacionales. Se ha conseguido determinar tamaño...

  15. "There's no chasing involved": cis/trans relationships, "tranny chasers," and the future of a sex-positive trans politics.

    Science.gov (United States)

    Tompkins, Avery Brooks

    2014-01-01

    This article adds to a small, but growing, body of work on trans sexualities and partnerships, and provides a much-needed inquiry into the complex and contested politics of desire when we take trans identities, bodies, and sexualities into account. Using digital ethnographic data from YouTube videos along with in-person observational data from LGBTQ and trans conferences in the U.S., Tompkins argues that a sex-positive trans politics cannot emerge in trans and trans-allied communities if the rhetoric of the "tranny chaser" continues to inform discourses of desire and attraction to trans people.

  16. Performance Analysis of the IEEE 802.11p Multichannel MAC Protocol in Vehicular Ad Hoc Networks.

    Science.gov (United States)

    Song, Caixia

    2017-12-12

    Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. The safety applications require timely and reliable transmissions, while the non-safety applications require efficient and high throughput. In the IEEE 1609.4 protocol, operating interval is divided into alternating Control Channel (CCH) interval and Service Channel (SCH) interval with an identical length. During the CCH interval, nodes transmit safety-related messages and control messages, and Enhanced Distributed Channel Access (EDCA) mechanism is employed to allow four Access Categories (ACs) within a station with different priorities according to their criticality for the vehicle's safety. During the SCH interval, the non-safety massages are transmitted. An analytical model is proposed in this paper to evaluate performance, reliability and efficiency of the IEEE 802.11p and IEEE 1609.4 protocols. The proposed model improves the existing work by taking serval aspects and the character of multichannel switching into design consideration. Extensive performance evaluations based on analysis and simulation help to validate the accuracy of the proposed model and analyze the capabilities and limitations of the IEEE 802.11p and IEEE 1609.4 protocols, and enhancement suggestions are given.

  17. IEEE Std 381-1977: IEEE standard criteria for type tests of Class 1E modules used in nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This document describes the basic requirements of a type test program with the objective of verifying that a module used as Class 1E equipment in a nuclear power generating station meets or exceeds its design specifications. This document is limited to class 1E modules from and including the sensor through the logic circuitry of the final actuation devices. Except for those that are part of a module, switchgear, cables, connections, motors, valve actuators, station batteries, and penetrations are not included and are covered by other IEEE documents. The purpose of this document is to supplement the procedures and requirements given in IEEE Std 323-1974 [24] for type testing Class 1E modules, thereby providing directions for establishment of a type test program which will obtain the required test data and yield the required documentation of test methods and results. This standard is structured to present to the user the principal performance characteristics and environmental parameters which must be considered in designing a type test program for any give Class 1E module. These modules range from tiny sensors to complete racks or cabinets full of equipment that may be located inside or outside containment. The Class 1E modules are required to perform their function before, during, or after, or all, any design basis event specified for the module. The vast variety of modules covered by this document precludes the listing here of specific requirements for each type test

  18. Effect of Trans, Trans-Farnesol on Pseudogymnoascus destructans and Several Closely Related Species.

    Science.gov (United States)

    Raudabaugh, Daniel B; Miller, Andrew N

    2015-12-01

    Bat white-nose syndrome, caused by the psychrophilic fungus Pseudogymnoascus destructans, has dramatically reduced the populations of many hibernating North American bat species. The search for effective biological control agents targeting P. destructans is of great importance. We report that the sesquiterpene trans, trans-farnesol, which is also a Candida albicans quorum sensing compound, prevented in vitro conidial germination for at least 14 days and inhibited growth of preexisting hyphae of five P. destructans isolates in filtered potato dextrose broth at 10 °C. Depending on the inoculation concentrations, both spore and hyphal inhibition occurred upon exposure to concentrations as low as 15-20 µM trans, trans-farnesol. In contrast, most North American Pseudogymnoascus isolates were more tolerant to the exposure of trans, trans-farnesol. Our results suggest that some Candida isolates may have the potential to inhibit the growth of P. destructans and that the sesquiterpene trans, trans-farnesol has the potential to be utilized as a biological control agent.

  19. Spark Plasma Sintering (SPS)-Assisted Synthesis and Thermoelectric Characterization of Magnéli Phase V6O11

    KAUST Repository

    Joos, Markus

    2018-01-11

    The Magnéli phase V6O11 was synthesized in gram amounts from a powder mixture of V6O11/V7O13 and vanadium metal, using the spark plasma sintering (SPS) technique. Its structure was determined with synchrotron X-ray powder diffraction data from a phase-pure sample synthesized by conventional solid-state synthesis. A special feature of Magnéli-type oxides is a combination of crystallographic shear and intrinsic disorder that leads to relatively low lattice thermal conductivities. SPS prepared V6O11 has a relatively low thermal conductivity of κ = 2.72 ± 0.06 W (m K)-1 while being a n-type conductor with an electrical conductivity of σ = 0.039 ± 0.005 (μΩ m)-1, a Seebeck coefficient of α = -(35 ± 2) μV K-1, which leads to a power factor of PF = 4.9 ± 0.8 × 10-5W (m K2)-1 at ∼600 K. Advances in the application of Magnéli phases are mostly hindered by synthetic and processing challenges, especially when metastable and nanostructured materials such as V6O11 are involved. This study gives insight into the complications of SPS-assisted synthesis of complex oxide materials, provides new information about the thermal and electrical properties of vanadium oxides at high temperatures, and supports the concept of reducing the thermal conductivity of materials with structural building blocks such as crystallographic shear (CS) planes.

  20. Spark Plasma Sintering (SPS)-Assisted Synthesis and Thermoelectric Characterization of Magnéli Phase V6O11

    KAUST Repository

    Joos, Markus; Cerretti, Giacomo; Veremchuk, Igor; Hofmann, Patrick; Frerichs, Hajo; Anjum, Dalaver H.; Reich, Tobias; Lieberwirth, Ingo; Panthö fer, Martin; Zeier, Wolfgang G.; Tremel, Wolfgang

    2018-01-01

    The Magnéli phase V6O11 was synthesized in gram amounts from a powder mixture of V6O11/V7O13 and vanadium metal, using the spark plasma sintering (SPS) technique. Its structure was determined with synchrotron X-ray powder diffraction data from a phase-pure sample synthesized by conventional solid-state synthesis. A special feature of Magnéli-type oxides is a combination of crystallographic shear and intrinsic disorder that leads to relatively low lattice thermal conductivities. SPS prepared V6O11 has a relatively low thermal conductivity of κ = 2.72 ± 0.06 W (m K)-1 while being a n-type conductor with an electrical conductivity of σ = 0.039 ± 0.005 (μΩ m)-1, a Seebeck coefficient of α = -(35 ± 2) μV K-1, which leads to a power factor of PF = 4.9 ± 0.8 × 10-5W (m K2)-1 at ∼600 K. Advances in the application of Magnéli phases are mostly hindered by synthetic and processing challenges, especially when metastable and nanostructured materials such as V6O11 are involved. This study gives insight into the complications of SPS-assisted synthesis of complex oxide materials, provides new information about the thermal and electrical properties of vanadium oxides at high temperatures, and supports the concept of reducing the thermal conductivity of materials with structural building blocks such as crystallographic shear (CS) planes.

  1. Avaliação por ressonância magnética de massas cardíacas

    Directory of Open Access Journals (Sweden)

    Maria Fernanda Braggion-Santos

    2013-09-01

    Full Text Available FUNDAMENTO: Tumores cardíacos são extremamente raros; no entanto, quando há suspeita clínica, é necessária a correta avaliação diagnóstica, para planejar o tratamento mais adequado. Nesse contexto, a ressonância magnética cardiovascular tem um papel importante, permitindo uma abrangente caracterização de tais lesões. OBJETIVO: Revisar os casos encaminhados a um Serviço de Ressonância Magnética para investigação de massas cardíacas e paracardíacas. Descrever a série de casos positivos, juntamente de uma breve revisão da literatura para cada tipo de lesão e sobre o papel da ressonância magnética cardiovascular em sua avaliação. MÉTODOS: Entre agosto de 2008 e dezembro de 2011, foram revistos todos os casos de pacientes encaminhados a ressonância magnética com suspeita de neoplasia envolvendo o coração. Foram selecionados aqueles com confirmação histopatológica, evolução ou resposta terapêutica compatíveis com a suspeita clínica e achados de imagem. RESULTADOS: Entre os 13 pacientes incluídos neste estudo, oito (62% tiveram confirmação histopatológica. Foram descritas cinco neoplasias benignas (mixomas, rabdomioma e fibromas, cinco neoplasias malignas (sarcoma, linfoma, síndrome de Richter cardíaca e doença metastática e três lesões não neoplásicas (cisto pericárdico, trombo intracardíaco e vegetação infecciosa. CONCLUSÃO: A informação disponível sobre essa questão é escassa. Estudos prospectivos adicionais são necessários para elucidar o papel desses nutrientes no risco cardiovascular de pacientes com diabetes.

  2. Aplicaciones de los registros de resonancia magnética nuclear (nmrl) en la evaluación de yacimientos

    OpenAIRE

    Landi Torres, Richard Paúl

    2008-01-01

    La extraordinaria tecnología de adquisición de registros o perfilaje de resonancia magnética nuclear (RMN) ha estado en continua evolución durante los últimos 10 años. Las compañías petroleras utilizan las mediciones de RMN en una variedad de aplicaciones cada vez más numerosa; por ejemplo, para caracterizar los fluidos de las formaciones durante la evolución de los yacimientos y determinar la producibilidad de la formación. Hoy en día, las mediciones obtenidas con estas herramien...

  3. Dinámica neuronal del circuito motor: un estudio de resonancia magnética funcional

    OpenAIRE

    Batista García-Ramó, Karla; Rodríguez Rojas, Rafael; Carballo Barreda, Maylén

    2012-01-01

    La modelación de redes neuronales que describan la interacción funcional del circuito cerebral formado por los ganglios basales (GB), el tálamo y la corteza está limitada por las simplificaciones necesarias para reproducir sus propiedades biológicas. Este trabajo tiene como objetivo general modelar el circuito GB-tálamo-corteza para la selección de un programa motor, sobre la base del patrón de conectividad funcional obtenido por imágenes de resonancia magnética nuclear funcional (RMNf). Se i...

  4. Sistema estabilizador da adesão de um robô escalador com rodas magnéticas

    OpenAIRE

    Espinoza, Rodrigo Valério

    2015-01-01

    Este trabalho consiste no desenvolvimento de um sistema estabilizador da adesão de um robô escalador com rodas magnéticas. O projeto deste robô surge da necessidade em automatizar o processo de inspeção de tanques de armazenamento de derivados de petróleo, o qual e atualmente realizado de modo manual. O robô vem sendo desenvolvido no Laboratório de Automação e Sistemas de Controle Avençado (LASCA) da Universidade Tecnológica Federal do Paraná (UTFPR). Primeiramente foi realizada uma análise t...

  5. Resultados de la resonancia magnética nuclear de cerebro en niños con cefalea

    OpenAIRE

    Gurkas, Esra; Karalok, Zeynep S; Taskm, Birce D; Aydogmus, Ummu; Yilmaz, Cahide; Bayram, Gulsah

    2017-01-01

    Introducción: El objetivo fue describir los resultados de la resonancia magnética nuclear (RMN) en niños con cefalea. Población y métodos: Revisión retrospectiva de las historias clínicas de los pacientes ingresados a los consultorios externos de neurología pediátrica con síntomas de cefalea entre enero de 2013 y diciembre de 2014. Resultados: Se ingresaron 478 pacientes (273 mujeres, 205 varones) con síntomas de cefalea. Los tipos de cefalea fueron migraña en 218 pacientes (45, 6%), cefalea ...

  6. Cis-trans photoisomerization of abscisic acid

    International Nuclear Information System (INIS)

    Brabham, D.E.; Biggs, R.H.

    1981-01-01

    An important regulator of numerous physiological processes in higher plants is abscisic acid (ABA), which is photoisomerized from the more biologically active cis isomer to the nearly inactive trans isomer by natural sunlight. It is possible that this photoisomerization is a UV control mechanism in functions regulated by ABA. The quantum yields of both the cis to trans and trans to cis photoisomerizations were measured under various conditions of pH and oxygen concentration at room temperature. The yield for photoisomerization of cis-ABA ranged from 0.25 at pH 3.0 to 0.11 at pH 7.0. Oxygen partially quenched the process. The quantum yield varied only slightly with wavelength. The quantum yield of photolysis of cis-ABA was reported for pH 3.0 as 0.06. This yield also varied slightly with wavelength and was relatively insensitive to oxygen. This relatively high yield explains the loss of potency of ABA during UV irradiation. Phosphorescence of cis- and trans-ABA was observed in methanol at 77 K. Onset of the emission was at 350 nm. The emission spectra were the same for both isomers. From these results a mechanism of UV action on plants based on the photoisomerization of the inactive trans-ABA to the biologically active cis isomer is proposed. (author)

  7. Trans Women Doing Sex in San Francisco.

    Science.gov (United States)

    Williams, Colin J; Weinberg, Martin S; Rosenberger, Joshua G

    2016-10-01

    This research investigates the sexuality of trans women (individuals who were assigned male status at birth who currently identify as women), by focusing on the "bodily techniques" (Crossley, 2006) they use in "doing" sexuality. The "doing sexuality" framework not only is modeled after the "doing gender" approach of West and Zimmerman (1987), but also utilizes the idea of "sexual embodiment" to emphasize the agency of trans women as they conceptualize and organize their sexuality in a socially recognized way. This is often difficult as they confront discrimination from medical and legal professionals as well as intimate partners who may find it difficult to adapt to the trans woman's atypical body and conception of gender. However, with a study group of 25 trans women from San Francisco, we found the study participants to be adept at overcoming such hurdles and developing techniques to "do" their sexuality. At the same time, we found trans women's agency constrained by the erotic habitus (Green, 2008) of the wider society. The interplay between innovation and cultural tradition provides an opportunity to fashion a more general model of "doing" sexuality.

  8. Trans issues in Liz Lochhead's 'Not Changed'

    Directory of Open Access Journals (Sweden)

    Kaličanin Milena M.

    2017-01-01

    Full Text Available The paper is divided into four sections. In the first section entitled 'Introducing and Defining Trans (Issues', the basic terms of transgender, transvestite, and transsexual are defined by relying on Stryker's Transgender History (2008. The second part of the paper, 'Trans Studies: In-Between Feminist and Queer Theory?', places transgender studies into an academic context by referring to the theoretical framework provided by trans theorists Stryker, Stone, and Ranck who unanimously claim that transgender studies should have a place of its own within the academia and that trans theory should solely be written by transsexuals. These ideas are applied in the interpretation of Lochhead's story 'Not Changed' in the third segment of the paper. The critical insights of Butler (Gender Trouble, 1990; Undoing Gender, 2004 are found to be most helpful in the interpretation of Lochhead's story about Michael who has willingly undergone Hormone Replacement Therapy to become transsexual Michele. Finally, in the concluding remarks, Lochhead's story is viewed as a trans woman manifesto, urging both non-transsexual and transsexual persons to embrace new beginnings in their relationship.

  9. Hybrid Polling Method for Direct Link Communication for IEEE 802.11 Wireless LANs

    Directory of Open Access Journals (Sweden)

    Woo-Yong Choi

    2008-10-01

    Full Text Available The direct link communication between STAtions (STAs is one of the techniques to improve the MAC performance of IEEE 802.11 infrastructure networks. For the efficient direct link communication, in the literature, the simultaneous polling method was proposed to allow the multiple direct data communication to be performed simultaneously. However, the efficiency of the simultaneous polling method is affected by the interference condition. To alleviate the problem of the lower polling efficiency with the larger interference range, the hybrid polling method is proposed for the direct link communication between STAs in IEEE 802.11 infrastructure networks. By the proposed polling method, we can integrate the sequential and simultaneous polling methods properly according to the interference condition. Numerical examples are also presented to show the medium access control (MAC performance improvement by the proposed polling method.

  10. 2011 IEEE Visualization Contest Winner: Visualizing Unsteady Vortical Behavior of a Centrifugal Pump

    KAUST Repository

    Otto, Mathias

    2012-09-01

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump\\'s effectiveness. The winning entry split analysis of the pump into three parts based on the pump\\'s functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/ oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump. © 2012 IEEE.

  11. The Exploration of Network Coding in IEEE 802.15.4 Networks

    Directory of Open Access Journals (Sweden)

    Deze Zeng

    2011-01-01

    communication protocol should be energy efficient. The IEEE 802.15.4 is designed as a standard protocol for low power, low data rate, low complexity, and short range connections in WPANs. The standard supports allocating several numbers of collision-free guarantee time slots (GTSs within a superframe for some time-critical transmissions. Recently, COPE was proposed as a promising network coding architecture to essentially improve the throughput of wireless networks. In this paper, we exploit the network coding technique at coordinators to improve energy efficiency of the WPAN. Some related practical issues, such as GTS allocation and multicast, are also discussed in order to exploit the network coding opportunities efficiently. Since the coding opportunities are mostly exploited, our proposal achieves both higher energy efficiency and throughput performance than the original IEEE 802.15.4.

  12. The IEEE 1355 Standard. Developments, performance and application in high energy physics

    International Nuclear Information System (INIS)

    Haas, S.

    1998-12-01

    The data acquisition systems of the next generation High Energy Physics experiments at the Large Hadron Collider (LHC) at CERN will rely on high-speed point-to-point links and switching networks for their higher level trigger and event building systems. This thesis provides a detailed evaluation of the DS-Link and switch technology, which is based on the IEEE 1355 standard for Heterogeneous Interconnect (HIC). The DS-Link is a bidirectional point-to-point serial interconnect, operating at speeds up to 200 MBaud. The objective of this thesis was to study the performance of the IEEE 1355 link and switch technology and to demonstrate that switching networks using this technology would scale to meet the requirements of the High Energy Physics applications

  13. VARNOST BREZŽIČNIH OMREŽIJ PO STANDARDU IEEE 802.11

    OpenAIRE

    Štumberger, Matej

    2013-01-01

    Diplomska naloga se osredotoča na problem varovanja brezžičnih omrežij, zasnovanih po standardu IEEE 802.11. Opisano je združenje IEEE in njihova specifikacija standardov z oznako 802, prav tako pa so opisani tudi standardi, protokoli in tehnike varovanja in zaščite omrežij, ki delujejo po tej specifikaciji. Predstavljeno je tudi trenutno stanje varnosti brezžičnih omrežij na področju mesta Ptuj, opisani in prikazani pa so tudi različni pristopi za zlorabo brezžičnih omrežij, skupaj s program...

  14. Design Optimization of Cyber-Physical Distributed Systems using IEEE Time-sensitive Networks (TSN)

    DEFF Research Database (Denmark)

    Pop, Paul; Lander Raagaard, Michael; Craciunas, Silviu S.

    2016-01-01

    to the optimization of distributed cyber-physical systems using real-time Ethernet for communication. Then, we formulate two novel optimization problems related to the scheduling and routing of TT and AVB traffic in TSN. Thus, we consider that we know the topology of the network as well as the set of TT and AVB flows......In this paper we are interested in safety-critical real-time applications implemented on distributed architectures supporting the Time-SensitiveNetworking (TSN) standard. The ongoing standardization of TSN is an IEEE effort to bring deterministic real-time capabilities into the IEEE 802.1 Ethernet...... standard supporting safety-critical systems and guaranteed Quality-of-Service. TSN will support Time-Triggered (TT) communication based on schedule tables, Audio-Video-Bridging (AVB) flows with bounded end-to-end latency as well as Best-Effort messages. We first present a survey of research related...

  15. Transient Stability Improvement of IEEE 9 Bus System Using Power World Simulator

    Directory of Open Access Journals (Sweden)

    Kaur Ramandeep

    2016-01-01

    Full Text Available The improvement of transient stability of power system was one of the most challenging research areas in power engineer.The main aim of this paper was transient stability analysis and improvement of IEEE 9 bus system. These studies were computed using POWER WORLD SIMULATOR. The IEEE 9 bus system was modelled in power world simulator and load flow studies were performed to determine pre-fault conditions in the system using Newton-Raphson method. The transient stability analysis was carried out using Runga method during three-phase balanced fault. For the improvement transient stability, the general methods adopted were fast acting exciters, FACT devices and addition of parallel transmission line. These techniques play an important role in improving the transient stability, increasing transmission capacity and damping low frequency oscillations.

  16. Integration of IEEE 1451 and HL7 exchanging information for patients' sensor data.

    Science.gov (United States)

    Kim, Wooshik; Lim, Suyoung; Ahn, Jinsoo; Nah, Jiyoung; Kim, Namhyun

    2010-12-01

    HL7 (Health Level 7) is a standard developed for exchanging incompatible healthcare information generated from programs or devices among heterogenous medical information systems. At present, HL7 is growing as a global standard. However, the HL7 standard does not support effective methods for treating data from various medical sensors, especially from mobile sensors. As ubiquitous systems are growing, HL7 must communicate with various medical transducers. In the area of sensor fields, IEEE 1451 is a group of standards for controlling transducers and for communicating data from/to various transducers. In this paper, we present the possibility of interoperability between the two standards, i.e., HL7 and IEEE 1451. After we present a method to integrate them and show the preliminary results of this approach.

  17. A note on bound constraints handling for the IEEE CEC'05 benchmark function suite.

    Science.gov (United States)

    Liao, Tianjun; Molina, Daniel; de Oca, Marco A Montes; Stützle, Thomas

    2014-01-01

    The benchmark functions and some of the algorithms proposed for the special session on real parameter optimization of the 2005 IEEE Congress on Evolutionary Computation (CEC'05) have played and still play an important role in the assessment of the state of the art in continuous optimization. In this article, we show that if bound constraints are not enforced for the final reported solutions, state-of-the-art algorithms produce infeasible best candidate solutions for the majority of functions of the IEEE CEC'05 benchmark function suite. This occurs even though the optima of the CEC'05 functions are within the specified bounds. This phenomenon has important implications on algorithm comparisons, and therefore on algorithm designs. This article's goal is to draw the attention of the community to the fact that some authors might have drawn wrong conclusions from experiments using the CEC'05 problems.

  18. Qualification of cables to IEEE standards 323-1974 and 383-1974

    International Nuclear Information System (INIS)

    Hosticka, C.; Kingsbury, E.R.; Bruhin, A.C.

    1980-01-01

    Wire and Cable manufacturers generally qualify products for class IE application by envelope type testing to user specifications and environmental conditions recommended by IEEE Standards 323-1974 and 383-1974. The General Electric Wire and Cable Business Department recently completed two such qualification programs. Cable constructions tested were 600V control cables and 600 V, 2kV, and 15kV power cables insulated with flame resistant mineral filled crosslinked polyethylene. The 15kV samples included taped field splices. In the second test program, the steam pressure-temperature profile included a simulated main steam line break. Test specimens were wrapped on grounded mandrels and were electrically loaded throughout the simulated LOCA tests. After completion of environmental testing, samples were subjected to the IEEE 383 simulated post-LOCA test. 6 refs

  19. Qualification of cables to IEEE standards 323-1974 and 383-1974

    International Nuclear Information System (INIS)

    Hosticka, C.; Kingsbury, E.R.; Bruhin, A.C.

    1980-01-01

    Wire and Cable manufacturers generally qualify products for class IE application by envelope type testing to user specifications and environmental conditions recommended by IEEE Standards 323-1974 and 383-1974. The General Electric Wire and Cable Business Department recently completed two such qualification programs. Cable constructions tested were 600V control cables and 600 V, 2KV, and 15KV power cables insulated with flame resistant mineral filled crosslinked polyethylene. The 15KV samples included taped field splices. In the second test program, the steam pressure-temperature profile included a simulated main steam line break. Test specimens were wrapped on grounded mandrels and were electrically loaded throughout the simulated LOCA tests. After completion of environmental testing, samples were subjected to the IEEE 383 simulated post-LOCA test. 6 refs

  20. A Novel IEEE 802.15.4e DSME MAC for Wireless Sensor Networks.

    Science.gov (United States)

    Sahoo, Prasan Kumar; Pattanaik, Sudhir Ranjan; Wu, Shih-Lin

    2017-01-16

    IEEE 802.15.4e standard proposes Deterministic and Synchronous Multichannel Extension (DSME) mode for wireless sensor networks (WSNs) to support industrial, commercial and health care applications. In this paper, a new channel access scheme and beacon scheduling schemes are designed for the IEEE 802.15.4e enabled WSNs in star topology to reduce the network discovery time and energy consumption. In addition, a new dynamic guaranteed retransmission slot allocation scheme is designed for devices with the failure Guaranteed Time Slot (GTS) transmission to reduce the retransmission delay. To evaluate our schemes, analytical models are designed to analyze the performance of WSNs in terms of reliability, delay, throughput and energy consumption. Our schemes are validated with simulation and analytical results and are observed that simulation results well match with the analytical one. The evaluated results of our designed schemes can improve the reliability, throughput, delay, and energy consumptions significantly.

  1. A Fast MAC-Layer Handover for an IEEE 802.16e-Based WMAN

    Science.gov (United States)

    Ray, Sayan K.; Pawlikowski, Krzysztof; Sirisena, Harsha

    We propose a modification of the IEEE 802.16e hard handover (HHO) procedure, which significantly reduces the handover latency constraint of the original HHO procedure in IEEE 802.16e networks. It allows a better handling of the delay-sensitive traffic by avoiding unnecessary time-consuming scanning and synchronization activity as well as simplifies the network re-entry procedure. With the help of the backhaul network, it reduces the number of control messages in the original handover policy, making the handover latency acceptable also for real-time streaming traffic. Preliminary performance evaluation studies show that the modified handover procedure is able to reduce the total handover latency by about 50%.

  2. A network architecture for precision formation flying using the IEEE 802.11 MAC Protocol

    Science.gov (United States)

    Clare, Loren P.; Gao, Jay L.; Jennings, Esther H.; Okino, Clayton

    2005-01-01

    Precision Formation Flying missions involve the tracking and maintenance of spacecraft in a desired geometric formation. The strong coupling of spacecraft in formation flying control requires inter-spacecraft communication to exchange information. In this paper, we present a network architecture that supports PFF control, from the initial random deployment phase to the final formation. We show that a suitable MAC layer for the application protocol is IEEE's 802.11 MAC protocol. IEEE 802.11 MAC has two modes of operations: DCF and PCF. We show that DCF is suitable for the initial deployment phase while switching to PCF when the spacecraft are in formation improves jitter and throughput. We also consider the effect of routing on protocol performance and suggest when it is profitable to turn off route discovery to achieve better network performance.

  3. Capacity Evaluation for IEEE 802.16e Mobile WiMAX

    Directory of Open Access Journals (Sweden)

    Chakchai So-In

    2010-01-01

    Full Text Available We present a simple analytical method for capacity evaluation of IEEE 802.16e Mobile WiMAX networks. Various overheads that impact the capacity are explained and methods to reduce these overheads are also presented. The advantage of a simple model is that the effect of each decision and sensitivity to various parameters can be seen easily. We illustrate the model by estimating the capacity for three sample applications—Mobile TV, VoIP, and data. The analysis process helps explain various features of IEEE 802.16e Mobile WiMAX. It is shown that proper use of overhead reducing mechanisms and proper scheduling can make an order of magnitude difference in performance. This capacity evaluation method can also be used for validation of simulation models.

  4. Estudio de la grasa de teobroma ozonizada usando la Resonancia Magnética

    Directory of Open Access Journals (Sweden)

    Fernández Torres, Irán

    2007-03-01

    Full Text Available Ozonation of theobroma fat at different applied ozone dosages was carried out and peroxide indexes along with antimicrobial activity were determined. The reaction products were identified using Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR. The principal signal intensity values were used for following the reaction course between ozone and theobroma fat. The reaction was followed up to peroxide index values of 544 mmol-equiv/kg. The intensities of olefinic proton signals decreased with the gradual increase in ozone concentration until disappearing completely. The Criegee ozonides obtained at 87.4 mg/g of ozone doses were approximately 3.7 times higher than at the beginning of the reaction. The highest action spectrum of antimicrobial activity was obtained with the higher peroxide index. These results suggest that the 1H NMR spectroscopic technique provides valuable information about of the ozonization grade of theobroma fat which produces an affective antimicrobial activity against Candida albicansSe realizó un estudio de la ozonización de la grasa de teobroma el cual fue seguido a diferentes dosis de ozono y fueron determinados los índices de peróxidos y su actividad antimicrobiana. Los productos de reacción fueron identificado por la espectroscopia de Resonancia Magnética Nuclear Protónica (RMN 1H. Los principales valores de intensidad de las señales fueron usados para el seguimiento de la reacción entre el ozono y la grasa de teobroma. La reacción fue seguida hasta un valor de índice de peróxidos de 1 544 mmolequiv/kg. Las intensidades de las señales de los protones olefínicos desaparecen con un gradual incremento de la concentración de ozono. Los ozónidos de Criegee obtenidos a dosis de ozono de 87,4 mg/g fueron 3,7 veces mayores que los obtenidos al inicio de la reacción. El mayor espectro de acción de la actividad antimicrobiana fue obtenido a mayor índice de peróxidos. Estos resultados sugieren que la t

  5. Contributions to the 14th IEEE/NPSS Symposium on fusion engineering

    International Nuclear Information System (INIS)

    Navarro, A.P.; Almoguera, L.; Alonso Gozalo, J.; Alonso Candenas, J.; Blaumoser, M.

    1992-01-01

    Three communications about the TJ-II device, under construction at CIEMAT with preferential support from EURATOM, were presented to the 14th IEEE/NPSS Symposium on Fusion Engineering and are collected in this report. The first one describes in detail the device and its present status of design and construction. The remaining two deal with the two most critical components of the project: the vacuum vessel and the central hard conductor. (author) 16 fig. 16 ref

  6. Utilizing reliability concepts in the development of IEEE recommended good practices for nuclear plant maintenance

    International Nuclear Information System (INIS)

    Gradin, L.P.

    1986-01-01

    This paper presents information describing the concern for nuclear power plant electrical equipment maintenance and the IEEE Nuclear Power Engineering Committee's method to address that concern. That method includes the creation of Working Group 3.3, ''Maintenance Good Practices'' which is developing specific maintenance good practice documents, supporting technical information exchange, and providing a vehicle to promote practices which can reduce cost and enhance plant safety. The foundation for that effort is the utilization of Reliability concepts

  7. Practical support for Lean Six Sigma software process definition using IEEE software engineering standards

    CERN Document Server

    Land, Susan K; Walz, John W

    2012-01-01

    Practical Support for Lean Six Sigma Software Process Definition: Using IEEE Software Engineering Standards addresses the task of meeting the specific documentation requirements in support of Lean Six Sigma. This book provides a set of templates supporting the documentation required for basic software project control and management and covers the integration of these templates for their entire product development life cycle. Find detailed documentation guidance in the form of organizational policy descriptions, integrated set of deployable document templates, artifacts required in suppo

  8. [Mobile Health: IEEE Standard for Wearable Cuffless Blood Pressure Measuring Devices].

    Science.gov (United States)

    Zhou, Xia; Wu, Wenli; Bao, Shudi

    2015-07-01

    IEEE Std 1708-2014 breaks through the traditional standards of cuff based blood pressure measuring devices and establishes a normative definition of wearable cuffless blood pressure measuring devices and the objective performance evaluation of this kind of devices. This study firstly introduces the background of the new standard. Then, the standard details will be described, and the impact of cuffless blood pressure measuring devices with the new standard on manufacturers and end users will be addressed.

  9. IEEE guide for general principles of reliability analysis of nuclear power generating station protection systems

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Presented is the Institute of Electrical and Electronics Engineers, Inc. (IEEE) guide for general principles of reliability analysis of nuclear power generating station protection systems. The document has been prepared to provide the basic principles needed to conduct a reliability analysis of protection systems. Included is information on qualitative and quantitative analysis, guides for failure data acquisition and use, and guide for establishment of intervals

  10. IEEE standard for qualifying class IE equipment for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1974-01-01

    The Institute of Electrical and Electrical Engineers, Inc. (IEEE) standards for electrical equipment (Class IE) for nuclear power generating stations are given. The standards are to provide guidance for demonstrating and documenting the adequacy of electric equipment used in all Class IE and interface systems. Representative in containment design basis event conditions for the principal reactor types are included in the appendixes for guidance in enviromental simulation

  11. An improved IEEE 802.11 protocol for reliable data transmission in power distribution fault diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Campoccia, F.; Di Silvestre, M.L.; Sanseverino, E.R.; Zizzo, G. [Palermo Univ., Palermo (Italy)

    2010-10-15

    In power systems, on-line transmission between local units and the central unit can be done by means of power line communications or wireless technology. During an electrical fault, the reliability of the distribution system depends on the security of the timely protective and restorative actions on the network. This paper focused on the WiFi system because of its economy and ease of installation. However, WiFi systems are typically managed by the IEEE 802.11 protocol, which is not reliable in terms of security in data communication. In WiFi networks, data is divided into packets and sent in succession to reduce errors within the radio channel. The IEEE 802.11 protocol has high probability for loss of packets or delay in their transmission. In order to ensure the reliability of data transmission times between two terminal units connected by WiFi stations, a new protocol was derived by modifying the IEEE 802.11. The improvements of the new protocol were highlighted and its capability for the diagnostic service was verified. The modified protocol eliminates the danger of collisions between packets and optimizes the transmission time for sending information. 6 refs., 7 tabs., 8 figs.

  12. FPGA implementation cost and performance evaluation of IEEE 802.11 protocol encryption security schemes

    Science.gov (United States)

    Sklavos, N.; Selimis, G.; Koufopavlou, O.

    2005-01-01

    The explosive growth of internet and consumer demand for mobility has fuelled the exponential growth of wireless communications and networks. Mobile users want access to services and information, from both internet and personal devices, from a range of locations without the use of a cable medium. IEEE 802.11 is one of the most widely used wireless standards of our days. The amount of access and mobility into wireless networks requires a security infrastructure that protects communication within that network. The security of this protocol is based on the wired equivalent privacy (WEP) scheme. Currently, all the IEEE 802.11 market products support WEP. But recently, the 802.11i working group introduced the advanced encryption standard (AES), as the security scheme for the future IEEE 802.11 applications. In this paper, the hardware integrations of WEP and AES are studied. A field programmable gate array (FPGA) device has been used as the hardware implementation platform, for a fair comparison between the two security schemes. Measurements for the FPGA implementation cost, operating frequency, power consumption and performance are given.

  13. Performance Evaluation of Beacon-Enabled Mode for IEEE 802.15.4 Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    M. Udin Harun Al Rasyid

    2013-12-01

    Full Text Available IEEE 802.15.5 standard support structure of star and peer-to-peer network formation. Strating from these, the cluster tree network can be built as a special case of peer-to-peer network to increse coverage area. In this paper, we provide an performance evaluation of beacon- enabled mode for IEEE 802.15.4 wireless sensor network on star and cluster topology in order to get the maximum result to apply the appropriate topology model as needed. We conduct analysis on each topology model by using the numbers of nodes from 10 nodes to 100 nodes to analyze throughput, delay, energy consumption, and probability success packet by using NS2 simulator. The simulation results show that the throughput and the probability of success packet of cluster topology are higher than that of star topology, and the energy consumption of cluster topology is lesser than that of star topology. However, cluster topology increases the delay more than star topology. Keywords: IEEE 802.15.4, wireless sensor network, beacon-enabled mode, topology, csma/ca

  14. Interoperability in digital electrocardiography: harmonization of ISO/IEEE x73-PHD and SCP-ECG.

    Science.gov (United States)

    Trigo, Jesús D; Chiarugi, Franco; Alesanco, Alvaro; Martínez-Espronceda, Miguel; Serrano, Luis; Chronaki, Catherine E; Escayola, Javier; Martínez, Ignacio; García, José

    2010-11-01

    The ISO/IEEE 11073 (x73) family of standards is a reference frame for medical device interoperability. A draft for an ECG device specialization (ISO/IEEE 11073-10406-d02) has already been presented to the Personal Health Device (PHD) Working Group, and the Standard Communications Protocol for Computer-Assisted ElectroCardioGraphy (SCP-ECG) Standard for short-term diagnostic ECGs (EN1064:2005+A1:2007) has recently been approved as part of the x73 family (ISO 11073-91064:2009). These factors suggest the coordinated use of these two standards in foreseeable telecardiology environments, and hence the need to harmonize them. Such harmonization is the subject of this paper. Thus, a mapping of the mandatory attributes defined in the second draft of the ISO/IEEE 11073-10406-d02 and the minimum SCP-ECG fields is presented, and various other capabilities of the SCP-ECG Standard (such as the messaging part) are also analyzed from an x73-PHD point of view. As a result, this paper addresses and analyzes the implications of some inconsistencies in the coordinated use of these two standards. Finally, a proof-of-concept implementation of the draft x73-PHD ECG device specialization is presented, along with the conversion from x73-PHD to SCP-ECG. This paper, therefore, provides recommendations for future implementations of telecardiology systems that are compliant with both x73-PHD and SCP-ECG.

  15. IEEE recommended practices for seismic qualification of Class 1E equipment for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The IEEE has developed this document to provide direction for developing programs to seismically qualify Class 1E equipment for nuclear power generating stations. It supplements IEEE Std 323-1974, IEEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations, which describes the basic requirements for equipment qualification. The Class 1E equipment to be qualified by produres or standards established by this document are of many forms, characteristics, and materials; therefore, the document presents many acceptable methods with the intent of permitting the user to make a judicious selection from among the various options. In making such a selection, the user should choose those that best meet a particular equipment's requirements. Further, in using this document as a specification for the purchase of equipment, the many options should also be recognized and the document invoked accordingly. It is recommended that the need for specific standards for the seismic qualifiction of particular kinds of equipment be evaluated by those responsible for such documents and that consideration be given to the application of particular methods from these documents which are most suitable

  16. IEEE P1596, a scalable coherent interface for GigaByte/sec multiprocessor applications

    International Nuclear Information System (INIS)

    Gustavson, D.B.

    1988-11-01

    IEEE P1596, the Scalable Coherent Interface (formerly known as SuperBus) is based on experience gained during the development of Fastbus (IEEE 960), Futurebus (IEEE 896.1) and other modern 32-bit buses. SCI goals include a minimum bandwidth of 1 GByte/sec per processor; efficient support of a coherent distributed-cache image of shared memory; and support for segmentation, bus repeaters and general switched interconnections like Banyan, Omega, or full crossbar networks. To achieve these ambitious goals, SCI must sacrifice the immediate handshake characteristic of the present generation of buses in favor of a packet-like split-cycle protocol. Wire-ORs, broadcasts, and even ordinary passive bus structures are to be avoided. However, a lower performance (1 GByte/sec per backplane instead of per processor) implementation using a register insertion ring architecture on a passive ''backplane'' appears to be possible using the same interface as for the more costly switch networks. This paper presents a summary of current directions, and reports the status of the work in progress

  17. Study on Additional Carrier Sensing for IEEE 802.15.4 Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Bih-Hwang Lee

    2010-06-01

    Full Text Available Wireless sensor networks based on the IEEE 802.15.4 standard are able to achieve low-power transmissions in the guise of low-rate and short-distance wireless personal area networks (WPANs. The slotted carrier sense multiple access with collision avoidance (CSMA/CA is used for contention mechanism. Sensor nodes perform a backoff process as soon as the clear channel assessment (CCA detects a busy channel. In doing so they may neglect the implicit information of the failed CCA detection and further cause the redundant sensing. The blind backoff process in the slotted CSMA/CA will cause lower channel utilization. This paper proposes an additional carrier sensing (ACS algorithm based on IEEE 802.15.4 to enhance the carrier sensing mechanism for the original slotted CSMA/CA. An analytical Markov chain model is developed to evaluate the performance of the ACS algorithm. Both analytical and simulation results show that the proposed algorithm performs better than IEEE 802.15.4, which in turn significantly improves throughput, average medium access control (MAC delay and power consumption of CCA detection.

  18. FPGA implementation cost and performance evaluation of IEEE 802.11 protocol encryption security schemes

    International Nuclear Information System (INIS)

    Sklavos, N; Selimis, G; Koufopavlou, O

    2005-01-01

    The explosive growth of internet and consumer demand for mobility has fuelled the exponential growth of wireless communications and networks. Mobile users want access to services and information, from both internet and personal devices, from a range of locations without the use of a cable medium. IEEE 802.11 is one of the most widely used wireless standards of our days. The amount of access and mobility into wireless networks requires a security infrastructure that protects communication within that network. The security of this protocol is based on the wired equivalent privacy (WEP) scheme. Currently, all the IEEE 802.11 market products support WEP. But recently, the 802.11i working group introduced the advanced encryption standard (AES), as the security scheme for the future IEEE 802.11 applications. In this paper, the hardware integrations of WEP and AES are studied. A field programmable gate array (FPGA) device has been used as the hardware implementation platform, for a fair comparison between the two security schemes. Measurements for the FPGA implementation cost, operating frequency, power consumption and performance are given

  19. Strategies for Optimal MAC Parameters Tuning in IEEE 802.15.6 Wearable Wireless Sensor Networks.

    Science.gov (United States)

    Alam, Muhammad Mahtab; Ben Hamida, Elyes

    2015-09-01

    Wireless body area networks (WBAN) has penetrated immensely in revolutionizing the classical heath-care system. Recently, number of WBAN applications has emerged which introduce potential limits to existing solutions. In particular, IEEE 802.15.6 standard has provided great flexibility, provisions and capabilities to deal emerging applications. In this paper, we investigate the application-specific throughput analysis by fine-tuning the physical (PHY) and medium access control (MAC) parameters of the IEEE 802.15.6 standard. Based on PHY characterizations in narrow band, at the MAC layer, carrier sense multiple access collision avoidance (CSMA/CA) and scheduled access protocols are extensively analyzed. It is concluded that, IEEE 802.15.6 standard can satisfy most of the WBANs applications throughput requirements by maximum achieving 680 Kbps. However, those emerging applications which require high quality audio or video transmissions, standard is not able to meet their constraints. Moreover, delay, energy efficiency and successful packet reception are considered as key performance metrics for comparing the MAC protocols. CSMA/CA protocol provides the best results to meet the delay constraints of medical and non-medical WBAN applications. Whereas, the scheduled access approach, performs very well both in energy efficiency and packet reception ratio.

  20. Study on additional carrier sensing for IEEE 802.15.4 wireless sensor networks.

    Science.gov (United States)

    Lee, Bih-Hwang; Lai, Ruei-Lung; Wu, Huai-Kuei; Wong, Chi-Ming

    2010-01-01

    Wireless sensor networks based on the IEEE 802.15.4 standard are able to achieve low-power transmissions in the guise of low-rate and short-distance wireless personal area networks (WPANs). The slotted carrier sense multiple access with collision avoidance (CSMA/CA) is used for contention mechanism. Sensor nodes perform a backoff process as soon as the clear channel assessment (CCA) detects a busy channel. In doing so they may neglect the implicit information of the failed CCA detection and further cause the redundant sensing. The blind backoff process in the slotted CSMA/CA will cause lower channel utilization. This paper proposes an additional carrier sensing (ACS) algorithm based on IEEE 802.15.4 to enhance the carrier sensing mechanism for the original slotted CSMA/CA. An analytical Markov chain model is developed to evaluate the performance of the ACS algorithm. Both analytical and simulation results show that the proposed algorithm performs better than IEEE 802.15.4, which in turn significantly improves throughput, average medium access control (MAC) delay and power consumption of CCA detection.

  1. On IEEE 802.15.6 IR-UWB receivers - simulations for DBPSK modulation.

    Science.gov (United States)

    Niemelä, Ville; Hämäläinen, Matti; Iinatti, Jari

    2013-01-01

    In 2002, Federal Communications Commission (FCC) was the first in defining regulations for ultra wideband (UWB) communications followed by Europe and Japan some years later. Focusing on impulse radio (IR) UWB, in 2007 was the time for the first published standard targeting in personal area networks, released by the IEEE. The second IEEE released standard including UWB definitions is targeted for wireless body area networks (WBAN) and was published in 2012. As the wireless communications has been and will be passing through almost any levels in society, the natural step with WBAN is using it in different medical, healthcare and wellbeing applications. The arguments for these are related to the modern lifestyle, in which people have increasingly more free time and are more interested in taking care of their health and wellbeing. Another challenge is the population composition, i.e., aging in developed countries which call for new solutions and procedures, particularly from cost wise. In this paper, we are evaluating UWB receivers based on the IEEE 802.15.6 physical layer definitions and capable of detecting differentially encoded modulation. The evaluation is performed using two different WBAN channel models.

  2. A versatile electrical penetration design qualified to IEEE Std. 317-1983

    International Nuclear Information System (INIS)

    Lankenau, W.; Wetherill, T.M.

    1994-01-01

    Although worldwide demand for new construction of nuclear power stations has been on a decline, the available opportunities for the design and construction of qualified electrical penetrations continues to offer challenges, requiring a highly versatile design. Versatility is necessary in order to meet unique customer requirements within the constraints of a design basis qualified to IEEE Std. 317-1983. This paper summarizes such a versatile electrical penetration designed, built and tested to IEEE Std. 317-1983. The principal features are described including major materials of construction. Some of the design constraints such as sealing requirements, and conductor density (including numerical example) are discussed. The requirements for qualification testing of the penetration assembly to IEEE Std. 317-1983 are delineated in a general sense, and some typical test ranges for preconditioning, radiation exposure, and LOCA are provided. The paper concludes by describing ways in which this versatile design has been adapted to meet unique customer requirements in a variety of nuclear power plants

  3. Segmentized Clear Channel Assessment for IEEE 802.15.4 Networks.

    Science.gov (United States)

    Son, Kyou Jung; Hong, Sung Hyeuck; Moon, Seong-Pil; Chang, Tae Gyu; Cho, Hanjin

    2016-06-03

    This paper proposed segmentized clear channel assessment (CCA) which increases the performance of IEEE 802.15.4 networks by improving carrier sense multiple access with collision avoidance (CSMA/CA). Improving CSMA/CA is important because the low-power consumption feature and throughput performance of IEEE 802.15.4 are greatly affected by CSMA/CA behavior. To improve the performance of CSMA/CA, this paper focused on increasing the chance to transmit a packet by assessing precise channel status. The previous method used in CCA, which is employed by CSMA/CA, assesses the channel by measuring the energy level of the channel. However, this method shows limited channel assessing behavior, which comes from simple threshold dependent channel busy evaluation. The proposed method solves this limited channel decision problem by dividing CCA into two groups. Two groups of CCA compare their energy levels to get precise channel status. To evaluate the performance of the segmentized CCA method, a Markov chain model has been developed. The validation of analytic results is confirmed by comparing them with simulation results. Additionally, simulation results show the proposed method is improving a maximum 8.76% of throughput and decreasing a maximum 3.9% of the average number of CCAs per packet transmission than the IEEE 802.15.4 CCA method.

  4. Spectrum Hole Identification in IEEE 802.22 WRAN using Unsupervised Learning

    Directory of Open Access Journals (Sweden)

    V. Balaji

    2016-01-01

    Full Text Available In this paper we present a Cooperative Spectrum Sensing (CSS algorithm for Cognitive Radios (CR based on IEEE 802.22Wireless Regional Area Network (WRAN standard. The core objective is to improve cooperative sensing efficiency which specifies how fast a decision can be reached in each round of cooperation (iteration to sense an appropriate number of channels/bands (i.e. 86 channels of 7MHz bandwidth as per IEEE 802.22 within a time constraint (channel sensing time. To meet this objective, we have developed CSS algorithm using unsupervised K-means clustering classification approach. The received energy level of each Secondary User (SU is considered as the parameter for determining channel availability. The performance of proposed algorithm is quantified in terms of detection accuracy, training and classification delay time. Further, the detection accuracy of our proposed scheme meets the requirement of IEEE 802.22 WRAN with the target probability of falsealrm as 0.1. All the simulations are carried out using Matlab tool.

  5. Analysis and Enhancement of IEEE 802.15.4e DSME Beacon Scheduling Model

    Directory of Open Access Journals (Sweden)

    Kwang-il Hwang

    2014-01-01

    Full Text Available In order to construct a successful Internet of things (IoT, reliable network construction and maintenance in a sensor domain should be supported. However, IEEE 802.15.4, which is the most representative wireless standard for IoT, still has problems in constructing a large-scale sensor network, such as beacon collision. To overcome some problems in IEEE 802.15.4, the 15.4e task group proposed various different modes of operation. Particularly, the IEEE 802.15.4e deterministic and synchronous multichannel extension (DSME mode presents a novel scheduling model to solve beacon collision problems. However, the DSME model specified in the 15.4e draft does not present a concrete design model but a conceptual abstract model. Therefore, in this paper we introduce a DSME beacon scheduling model and present a concrete design model. Furthermore, validity and performance of DSME are evaluated through experiments. Based on experiment results, we analyze the problems and limitations of DSME, present solutions step by step, and finally propose an enhanced DSME beacon scheduling model. Through additional experiments, we prove the performance superiority of enhanced DSME.

  6. A Novel Prioritization Scheme to Improve QoS in IEEE 802.11e Networks

    Directory of Open Access Journals (Sweden)

    Navid Tadayon

    2010-01-01

    Full Text Available IEEE 802.11 WLAN utilizes a distributed function at its MAC layer, namely, DCF to access the wireless medium. Due to its distributed nature, DCF is able to guarantee working stability in a wireless medium while maintaining the assembling and maintenance cost in a low level. However, DCF is inefficient in dealing with real-time traffics due to its incapability on providing QoS. IEEE 802.11e was introduced as a supplementary standard to cope with this problem. This standard introduces an Enhanced Distributed Coordination Function (EDCF that works based on diff-Serve model and can serve multiple classes of traffics (by using different prioritizations schemes. With the emergence of new time-sensitive applications, EDCF has proved to be yet inefficient in dealing with these kinds of traffics because it could not provide network with well-differentiated QoS. In this study, we propose a novel prioritization scheme to improve QoS level in IEEE 802.11e network. In this scheme, we replace Uniform PDF with Gamma PDF, which has salient differentiating properties. We investigate the suitability and superiority of this scheme on furnishing network with well-differentiated QoS using probabilistic analysis. We strengthen our claims by extensive simulation runs.

  7. IEEE 693 seismic qualification of composites for substation high-voltage equipment

    Energy Technology Data Exchange (ETDEWEB)

    Schiff, A.J. [Precision Measurement Instruments, Los Altos Hills, CA (United States); Kempner, L.Jr. [Bonneville Power Administration, Vancouver, BC (Canada)

    2004-07-01

    Standard 693-1997 of the Institute of Electrical and Electronic Engineers (IEEE) is the recommended practice for seismic design of substations. It represents a significant improvement in the way the power industry seismically qualifies substation high-voltage equipment. This paper described the use of IEEE Standard 693 for hollow-core composite insulators that are used on high-voltage transformers and demonstrated that changes are warranted. The following four failure modes associated with the composite insulator were discussed: bond degradation, bond failure, tube degradation and tube layer delamination. The authors evaluated the IEEE 693 qualification procedure of time history shake-table and static-pull tests and were concerned about acceptance criteria. It was shown that acceptance criteria are not valid for qualifying hollow-core composites and that static-pull tests are needed after the vibration qualification tests are completed. It was suggested that more research is warranted to determine if bonding at the top part of the flange can be eliminated, thereby eliminating bond degradation. The resulting increase in system damping would improve the dynamic response of the unit. 1 ref., 10 figs.

  8. Technical aspects of trans reduction in margarines

    Directory of Open Access Journals (Sweden)

    Van Duijn Gerrit

    2000-01-01

    Full Text Available The opinion of nutritional science on the effect of trans fatty acids on blood cholesterol has drastically changed during the last decade. As a reaction to these new findings, the European margarine industry decided in the mid nineties to eliminate trans containing components from their margarine fat phase compositions. This excluded practically the use of partially hydrogenated oils and fats. Trans-free margarines have been introduced with optimised fat crystal structures stabilising a maximum of water in oil emulsion with a minimum of solid fat phase. These fat crystal structures are formed by fat phase components obtained from interesterification and/or fractionation of non-hydrogenated and/or fully hydrogenated feedstocks.

  9. Physics of Trans-Planckian Gravity

    CERN Document Server

    Dvali, Gia; Germani, Cristiano

    2011-01-01

    We study aspects of the phenomenon of gravitational UV-self-completeness and its implications for deformations of Einstein gravity. In a ghost-free theory flowing to Einstein gravity in the IR trans-Planckian propagating quantum degrees of freedom cannot exist. The only physical meaning of a trans-Planckian pole is the one of a classical state (Black Hole) which is fully described by the light IR quantum degrees of freedom and gives exponentially-suppressed contributions to virtual processes. In this sense Einstein gravity is UV self-complete, although not Wilsonian. We show that this UV/IR correspondence puts a severe constraint on any attempt of conventional Wilsonian UV-completion of trans-Planckian gravity. In particular, there is no well-defined energy domain in which gravity could become asymptotically weak or safe.

  10. Da deflexão de raios cósmicos ultra-energéticos no campo magnético galáctico

    OpenAIRE

    Rafael Alves Batista

    2012-01-01

    Resumo: Campos magnéticos cósmicos são ubíquos e estão presentes em todas as escalas, desde os planetas até os superaglomerados de galáxias. Sabe-se que o campo magnético da Via Láctea possui uma componente regular, que tem uma estrutura espiral, e uma componente aleatória. Muitas questões acerca do magnetismo galáctico ainda permanecem sem respostas, e o modelo de espiral mais adequado para descrever as observações é incógnito. Uma possibilidade pouco explorada para estudar o campo magnético...

  11. Ruminant and industrially produced trans fatty acids

    DEFF Research Database (Denmark)

    Stender, Steen; Astrup, Arne; Dyerberg, Jørn

    2008-01-01

    % of the fatty acids in trans form compared to the content in ruminant fat which generally does not exceed 6%. In Western Europe, including Scandinavia, the average daily intake of IP-TFA has decreased during the recent decade due to societal pressure and a legislative ban, whereas the intake of RP-TFA has......Fatty acids of trans configuration in our food come from two different sources - industrially produced partially hydrogenated fat (IP-TFA) used in frying oils, margarines, spreads, and in bakery products, and ruminant fat in dairy and meat products (RP-TFA). The first source may contain up to 60...

  12. Comparación de un control lineal y no lineal en un levitador magnético

    Directory of Open Access Journals (Sweden)

    Jonathan Smith Castro Beltrán

    2018-02-01

    Full Text Available El artículo presenta los diseños y resultados de dos controladores tipo SISO de posición para un levitador magnético convencional, con la motivación de comparar las dinámicas de los sistemas posterior a la implementación de ambos métodos de control. Para el diseño de los controladores se obtuvo el modelo matemático aproximado de un levitador magnético a partir de características estáticas, de fuerza electromagnética e inductancia. Una vez establecido el modelo matemático se planteó una ley de control lineal a partir de una realimentación de estados con integrador, estimando la velocidad y corriente. Para el diseño del control no lineal se propuso una ley de control de tipo linealización entrada salida. Por último, se comparó la dinámica del sistema con los controladores implementados y se realizaron modificaciones de masa para verificar la robustez de los controladores, además de perturbaciones tales como fuerzas externas y ruido de tipo eléctrico. Finalmente, fue posible concluir que el controlador lineal tiene una respuesta satisfactoria en términos de error de estado estacionario, añadiendo un menor costo de procesamiento en comparación al controlador no lineal.

  13. Influencia del campo magnético estático en la turbidez de la cerveza de alta gravedad

    Directory of Open Access Journals (Sweden)

    Matilde Anaya Villalpanda

    2013-12-01

    Full Text Available Se aplicó el campo magnético estático a la cerveza de alta gravedad en tres etapas distintas del proceso, a partir de un diseño multifactorial D-óptimo de tres factores (intensidad de corriente, tiempo de residencia y tipo de cerveza. Se determinó la turbidez variable de respuesta por la diferencia de absorbancia por espectrofotometría a 580 nm. Se obtuvo un modelo lineal en los rangos evaluados que relaciona dicha variable con el régimen de tratamiento magnético con efecto significativo sobre la aglutinación de las partículas coloidales en suspensión lo cual favorece la clarificación. La mejor combinación de factores estuvo en el rango de 0,40-0,55 A (100-120 mT y tiempo de residencia 10 s en la cerveza no diluida y en la diluida, sin afectación de las características sensoriales.

  14. Modelización, Análisis y Control de Sistemas de Cojinetes Magnéticos Activos

    Directory of Open Access Journals (Sweden)

    I. Arredondo

    2008-10-01

    Full Text Available Resumen: En este estudio se presentan el modelado, diseño de control, análisis de robustez y procedimiento de reducción activa de vibraciones de un sistema consistente en un eje sustentado mediante levitación magnética activa. Primero se describen la obtención del modelo y las características fundamentales del sistema. Empleando dicho modelo y aprovechando propiedades de simetría, se diseña un control de sustentación. Este se ajusta experimentalmente mediante un estudio de robustez, según el estándar ISO 14839-3. Por último, se realiza una reducción de las vibraciones que se producen en rotación, utilizando control adaptativo. El controlador final diseñado ha sido implementado experimentalmente con éxito. Palabras Clave: Cojinetes magnéticos, Modelado, Robustez, Control Activo, Máquina Herramienta

  15. A geometria do campo magnético na região da nuvem Lupus 1

    Science.gov (United States)

    Alves, F. P.; Franco, G. A. P.

    2003-08-01

    Apresentaremos os resultados de uma investigação polarimétrica na região de formação estelar junto à nuvem escura Lupus 1. Esse estudo baseia-se em polarimétria CCD obtida na banda R, e cobre Lupus 1, bem como a área vizinha a essa nuvem contendo a cavidade em 100 mm IRAS. Os dados observacionais foram coletados com o telescópio IAG de 60 cm do Observatório do Pico dos Dias (LNA/MCT - Brasópolis - MG). Nossa primeira análise mostra que uma variação da orientação do campo magnético através da região pode produzir padrões complexos de polarização cuja geometria do campo não pode ser facilmente determinada. Os padrões de polarização são inconsistentes com um campo magnético estritamente uniforme e unidimensional em larga escala. Comparação com a emissão em 100 mm mostra que localmente os vetores de polarização exibem um forte alinhamento com a orientação dos padrões observados em infravermelho.

  16. Endometriose pleural: achados na ressonância magnética Pleural endometriosis: findings on magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Edson Marchiori

    2012-12-01

    Full Text Available A endometriose é uma doença ginecológica benigna associada à dor pélvica e infertilidade que afeta principalmente mulheres em idade reprodutiva. A endometriose torácica afeta o parênquima pulmonar ou a pleura. Relatamos os casos de duas pacientes com endometriose pleural que apresentaram pneumotórax recorrente. Em ambos os casos, a ressonância magnética de tórax mostrou hidropneumotórax à direita e nódulos redondos, bem definidos, na superfície pleural à direita. A ressonância magnética é uma boa opção para a caracterização dos nódulos de endometriose pleural e de derrame pleural hemorrágico.Endometriosis is a benign gynecological disorder associated with pelvic pain and infertility, primarily affecting women of reproductive age. Thoracic endometriosis affects the pulmonary parenchyma or pleura. We report the cases of two patients with pleural endometriosis who presented with recurrent pneumothorax. In both cases, magnetic resonance imaging (MRI of the chest showed right hydropneumothorax and well-defined, rounded nodules on the pleural surface in the right hemithorax. We conclude that MRI is a good option for the characterization of pleural endometriotic nodules and hemorrhagic pleural effusion.

  17. Discovery and ramifications of incidental Magnéli phase generation and release from industrial coal-burning.

    Science.gov (United States)

    Yang, Yi; Chen, Bo; Hower, James; Schindler, Michael; Winkler, Christopher; Brandt, Jessica; Di Giulio, Richard; Ge, Jianping; Liu, Min; Fu, Yuhao; Zhang, Lijun; Chen, Yuru; Priya, Shashank; Hochella, Michael F

    2017-08-08

    Coal, as one of the most economic and abundant energy sources, remains the leading fuel for producing electricity worldwide. Yet, burning coal produces more global warming CO 2 relative to all other fossil fuels, and it is a major contributor to atmospheric particulate matter known to have a deleterious respiratory and cardiovascular impact in humans, especially in China and India. Here we have discovered that burning coal also produces large quantities of otherwise rare Magnéli phases (Ti x O 2x-1 with 4 ≤ x ≤ 9) from TiO 2 minerals naturally present in coal. This provides a new tracer for tracking solid-state emissions worldwide from industrial coal-burning. In its first toxicity testing, we have also shown that nanoscale Magnéli phases have potential toxicity pathways that are not photoactive like TiO 2 phases, but instead seem to be biologically active without photostimulation. In the future, these phases should be thoroughly tested for their toxicity in the human lung.Solid-state emissions from coal burning remain an environmental concern. Here, the authors have found that TiO2 minerals present in coal are converted into titanium suboxides during burning, and initial biotoxicity screening suggests that further testing is needed to look into human lung consequences.

  18. Conference Proceedings for 1997 IEEE 24th International Conference on Plasma Sciences, 19 - 22 May 1997, San Diego, California

    National Research Council Canada - National Science Library

    Hyman, Julius

    1997-01-01

    This 360 page softbound publication includes the following major sections, An invitation to ICOPS'97, Catamaran Resort Hotel Floor Pinas, Officers of the IEEE Nuclear and Plasma Sciences Society, Conference Information...

  19. NIH-IEEE 2015 Strategic Conference on Healthcare Innovations and Point-of-Care Technologies for Prec

    Science.gov (United States)

    NIH and the Institute for Electrical and Electronics Engineering, Engineering in Medicine and Biology Society (IEEE/EMBS) hosted the third iteration of the Healthcare Innovations and Point-of-Care Technologies Conference last week.

  20. Study of Allocation Guaranteed Time Slot Wireless Body Area Networks Based on IEEE 802.15.4

    Science.gov (United States)

    Yundra, E.; Harsono, G. D.

    2018-04-01

    This paper aims to determine the size of the Guaranteed Time Slot (GTS) on the super frame structure required for each sensor as well as to know the performance of the GTS resized system compared to the GTS standard on IEEE 802.15.4. This article proposes a scheme to improve IEEE 802.15.4 medium access control, called allocation Guaranteed Time Slot (ALGATIS). ALGATIS is expected to effectively allocate guaranteed time slot to the requested sensors, it adjusts the length of the slot in super frame duration based on the length of the packet data. This article presents a simulation experiment of IEEE 802.15.4, especially for star network, to predict the throughput of networks and average energy consumption. The simulation experiments show that the performance of ALGATIS is better than that of IEEE 802.15.4 standard in term of the throughput of networks and average energy consumption

  1. Performance Analysis of IEEE 802.11g TCM Waveforms Transmitted over a Channel with Pulse-Noise Interference

    National Research Council Canada - National Science Library

    Drivas, Athanasios

    2007-01-01

    .... The application of TCM combines FEC coding and M-ary modulation in one operation. The objective of this thesis is to investigate the performance of an orthogonal frequency-division multiplexing (OFDM) based IEEE...

  2. Implementation of DoS attack and mitigation strategies in IEEE 802.11b/g WLAN

    Science.gov (United States)

    Deng, Julia; Meng, Ke; Xiao, Yang; Xu, Roger

    2010-04-01

    IEEE 802.11 wireless Local Area Network (WLAN) becomes very prevalent nowadays. Either as a simple range extender for a home wired Ethernet interface, or as a wireless deployment throughout an enterprise, WLAN provides mobility, convenience, and low cost. However, an IEEE 802.11b/g wireless network uses the frequency of unlicensed 2.4GHz, which makes the network unsafe and more vulnerable than traditional Ethernet networks. As a result, anyone who is familiar with wireless network may initiate a Denial of Service (DoS) attack to influence the common communication of the network or even make it crash. In this paper, we present our studies on the DoS attacks and mitigation strategies for IEEE 802.11b/g WLANs and describe some initial implementations using IEEE 802.11b/g wireless devices.

  3. Implementation of IEEE-1588 timing and synchronization for ATCA control and data acquisition systems

    International Nuclear Information System (INIS)

    Correia, Miguel; Sousa, Jorge; Combo, Álvaro; Rodrigues, António P.; Carvalho, Bernardo B.; Batista, António J.N.; Gonçalves, Bruno; Correia, Carlos M.B.A.; Varandas, Carlos A.F.

    2012-01-01

    Highlights: ► IEEE-1588 over Ethernet protocol is implemented for the synchronization of all clock signals of an ATCA AMC carrier module. ► The ATCA hardware consists of an AMC quad-carrier main-board with PCI Express switching. ► IEEE-1588 is to be implemented on a Virtex-6 FPGA. ► Timing signals on the ATX-AMC4-PTP are managed and routed by a crosspoint-switch implemented on a Virtex-6 FPGA. ► Each clock signal source may be independently located (on each of the AMC cards, RTM or ATCA backplane). - Abstract: Control and data acquisition (C and DA) systems for Fusion experiments are required to provide accurate timing and synchronization (T and S) signals to all of its components. IPFN adopted PICMG's Advanced Telecommunications Computing Architecture (ATCA) industry standard to develop C and DA instrumentation. ATCA was chosen not only for its high throughput characteristics but also for its high availability (HA) features which become of greater importance in steady-state operation scenarios. However, the specified ATCA clock and synchronization interface may be too limited for the timing and synchronization needs in advanced Physics experiments. Upcoming specification extensions, developed by the “xTCA for Physics” workgroups, will contemplate, among others, a complementary timing specification, developed by the PICMG xTCA for Physics IO, Timing and Synchronization Technical Committee. The IEEE-1588 Precision Time Protocol (PTP) over Ethernet is one of the protocols, proposed by the Committee, aiming for precise synchronization of clocks in measurement and control systems, based on low jitter and slave-to-slave skew criteria. The paper presents an implementation of IEEE-1588 over Ethernet, in an ATCA hardware platform. The ATCA hardware consists of an Advanced Mezzanine Card (AMC) quad-carrier front board with PCI Express switching. IEEE-1588 is to be implemented on a Virtex-6 FPGA. Ethernet connectivity with the remote master clock is located on

  4. Biotransformation of trans-1-chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd)

    International Nuclear Information System (INIS)

    Schmidt, Tobias; Bertermann, Rüdiger; Rusch, George M.; Tveit, Ann; Dekant, Wolfgang

    2013-01-01

    trans-1-Chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd) is a novel foam blowing and precision cleaning agent with a very low impact for global warming and ozone depletion. trans-HCFO-1233zd also has a low potential for toxicity in rodents and is negative in genotoxicity testing. The biotransformation of trans-HCFO-1233zd and kinetics of metabolite excretion with urine were assessed in vitro and in animals after inhalation exposures. For in vitro characterization, liver microsomes from rats, rabbits and humans were incubated with trans-HCFO-1233zd. Male Sprague Dawley rats and female New Zealand White rabbits were exposed to 2,000, 5,000 and 10,000 ppm for 6 h and urine was collected for 48 h after the end of the exposure. Study specimens were analyzed for metabolites using 19 F NMR, LC-MS/MS and GC/MS. S-(3,3,3-trifluoro-trans-propenyl)-glutathione was identified as predominant metabolite of trans-HCFO-1233zd in all microsomal incubation experiments in the presence of glutathione. Products of the oxidative biotransformation of trans-HCFO-1233zd were only minor metabolites when glutathione was present. In rats, both 3,3,3-trifluorolactic acid and N-acetyl-(3,3,3-trifluoro-trans-propenyl)-L-cysteine were observed as major urinary metabolites. 3,3,3-Trifluorolactic acid was not detected in the urine of rabbits. Quantitation showed rapid excretion of both metabolites in both species (t 1/2 1/2 < 6 h). ► Glutathione adduct as predominant in vitro metabolite in all tested species. ► Toxic metabolites could not be detected in any great extent

  5. Diseño de metodologías para la adquisición de resonancia magnética funcional a 1,5t

    OpenAIRE

    Guiu Hernández, Esther

    2009-01-01

    Projecte fet en col.laboració amb Pontificia Universidad Católica de Chile. Escuela de Ingeniería La resonancia magnética funcional (fMRI) es una técnica mediante la cual se puede mapear el cerebro, tanto anatómica como fisiológicamente, sin necesidad de realizar estudios invasivos. A fin de obtener mapas de activación cerebral, el sujeto en estudio debe realizar alguna tarea o estar expuesto a un estímulo externo. Paralelamente se adquieren, mediante resonancia magnética, una gran cantida...

  6. Biotransformation of trans-1-chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd)

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Tobias [Institut für Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg (Germany); Bertermann, Rüdiger [Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg (Germany); Rusch, George M.; Tveit, Ann [Honeywell, P.O. Box 1057, Morristown, NJ 07962-1057 (United States); Dekant, Wolfgang, E-mail: dekant@toxi.uni-wuerzburg.de [Institut für Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg (Germany)

    2013-05-01

    trans-1-Chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd) is a novel foam blowing and precision cleaning agent with a very low impact for global warming and ozone depletion. trans-HCFO-1233zd also has a low potential for toxicity in rodents and is negative in genotoxicity testing. The biotransformation of trans-HCFO-1233zd and kinetics of metabolite excretion with urine were assessed in vitro and in animals after inhalation exposures. For in vitro characterization, liver microsomes from rats, rabbits and humans were incubated with trans-HCFO-1233zd. Male Sprague Dawley rats and female New Zealand White rabbits were exposed to 2,000, 5,000 and 10,000 ppm for 6 h and urine was collected for 48 h after the end of the exposure. Study specimens were analyzed for metabolites using {sup 19}F NMR, LC-MS/MS and GC/MS. S-(3,3,3-trifluoro-trans-propenyl)-glutathione was identified as predominant metabolite of trans-HCFO-1233zd in all microsomal incubation experiments in the presence of glutathione. Products of the oxidative biotransformation of trans-HCFO-1233zd were only minor metabolites when glutathione was present. In rats, both 3,3,3-trifluorolactic acid and N-acetyl-(3,3,3-trifluoro-trans-propenyl)-L-cysteine were observed as major urinary metabolites. 3,3,3-Trifluorolactic acid was not detected in the urine of rabbits. Quantitation showed rapid excretion of both metabolites in both species (t{sub 1/2} < 6 h) and the extent of biotransformation of trans-HCFO-1233zd was determined as approximately 0.01% of received dose in rabbits and approximately 0.002% in rats. trans-HCFO-1233zd undergoes both oxidative biotransformation and glutathione conjugation at very low rates. The low extent of biotransformation and the rapid excretion of metabolites formed are consistent with the very low potential for toxicity of trans-HCFO-1233zd in mammals. - Highlights: ► No lethality and clinical signs were observed. ► Glutathione S-transferase and cytochrome P-450 dependent

  7. Powdered activated carbon adsorption of two fishy odorants in water: Trans,trans-2,4-heptadienal and trans,trans-2,4-decadienal.

    Science.gov (United States)

    Li, Xin; Wang, Jun; Zhang, Xiaojian; Chen, Chao

    2015-06-01

    Powdered activated carbon (PAC) adsorption of two fishy odorants, trans,trans-2,4-heptadienal (HDE) and trans,trans-2,4-decadienal (DDE), was investigated. Both the pseudo first-order and the pseudo second-order kinetic models well described the kinetics curves, and DDE was more readily removed by PAC. In isotherm tests, both Freundlich and Modified Freundlich isotherms fitted the experimental data well. PAC exhibited a higher adsorption capacity for DDE than for HDE, which could be ascribed to the difference in their hydrophobicity. The calculated thermodynamic parameters (ΔG0, ΔH0, and ΔS0) indicated an exothermic and spontaneous adsorption process. PAC dosage, pH, and natural organic matter (NOM) presence were found to influence the adsorption process. With increasing PAC dosage, the pseudo first-order and pseudo second-order rate constants both increased. The value of pH had little influence on HDE or DDE molecules but altered the surface charge of PAC, and the maximum adsorption capacity occurred at pH9. The presence of NOM, especially the fraction with molecular weight less than 1k Dalton, hindered the adsorption. The study showed that preloaded NOM impaired the adsorption capacity of HDE or DDE more severely than simultaneously fed NOM did. Copyright © 2015. Published by Elsevier B.V.

  8. Trans-kingdom cross-talk

    DEFF Research Database (Denmark)

    Knip, Marijn; Constantin, Maria-Ermioni; Thordal-Christensen, Hans

    2014-01-01

    This review focuses on the mobility of small RNA (sRNA) molecules from the perspective of trans-kingdom gene silencing. Mobility of sRNA molecules within organisms is a well-known phenomenon, facilitating gene silencing between cells and tissues. sRNA signals are also transmitted between organism...

  9. The european Trans-Tools transport model

    NARCIS (Netherlands)

    Rooijen, T. van; Burgess, A.

    2008-01-01

    The paper presents the use of ArcGIS in the Transtools Transport Model, TRANS-TOOLS, created by an international consortium for the European Commission. The model describe passenger as well as freight transport in Europe with all medium and long distance modes (cars, vans, trucks, train, inland

  10. Trans-Kullo jagatakse tükkideks / Kadrin Karner

    Index Scriptorium Estoniae

    Karner, Kadrin

    2008-01-01

    Primos OÜ omanik ja Trans-Kullo osanik Endel Siff ütles, et Trans-Kullo on aktsionäride erinevate ärihuvide tõttu läinud jagunemisele, mis võib lõppeda ettevõtte likvideerimisega. Lisa: Trans-Kullo

  11. DoS detection in IEEE 802.11 with the presence of hidden nodes

    Directory of Open Access Journals (Sweden)

    Joseph Soryal

    2014-07-01

    Full Text Available The paper presents a novel technique to detect Denial of Service (DoS attacks applied by misbehaving nodes in wireless networks with the presence of hidden nodes employing the widely used IEEE 802.11 Distributed Coordination Function (DCF protocols described in the IEEE standard [1]. Attacker nodes alter the IEEE 802.11 DCF firmware to illicitly capture the channel via elevating the probability of the average number of packets transmitted successfully using up the bandwidth share of the innocent nodes that follow the protocol standards. We obtained the theoretical network throughput by solving two-dimensional Markov Chain model as described by Bianchi [2], and Liu and Saadawi [3] to determine the channel capacity. We validated the results obtained via the theoretical computations with the results obtained by OPNET simulator [4] to define the baseline for the average attainable throughput in the channel under standard conditions where all nodes follow the standards. The main goal of the DoS attacker is to prevent the innocent nodes from accessing the channel and by capturing the channel’s bandwidth. In addition, the attacker strives to appear as an innocent node that follows the standards. The protocol resides in every node to enable each node to police other nodes in its immediate wireless coverage area. All innocent nodes are able to detect and identify the DoS attacker in its wireless coverage area. We applied the protocol to two Physical Layer technologies: Direct Sequence Spread Spectrum (DSSS and Frequency Hopping Spread Spectrum (FHSS and the results are presented to validate the algorithm.

  12. DoS detection in IEEE 802.11 with the presence of hidden nodes.

    Science.gov (United States)

    Soryal, Joseph; Liu, Xijie; Saadawi, Tarek

    2014-07-01

    The paper presents a novel technique to detect Denial of Service (DoS) attacks applied by misbehaving nodes in wireless networks with the presence of hidden nodes employing the widely used IEEE 802.11 Distributed Coordination Function (DCF) protocols described in the IEEE standard [1]. Attacker nodes alter the IEEE 802.11 DCF firmware to illicitly capture the channel via elevating the probability of the average number of packets transmitted successfully using up the bandwidth share of the innocent nodes that follow the protocol standards. We obtained the theoretical network throughput by solving two-dimensional Markov Chain model as described by Bianchi [2], and Liu and Saadawi [3] to determine the channel capacity. We validated the results obtained via the theoretical computations with the results obtained by OPNET simulator [4] to define the baseline for the average attainable throughput in the channel under standard conditions where all nodes follow the standards. The main goal of the DoS attacker is to prevent the innocent nodes from accessing the channel and by capturing the channel's bandwidth. In addition, the attacker strives to appear as an innocent node that follows the standards. The protocol resides in every node to enable each node to police other nodes in its immediate wireless coverage area. All innocent nodes are able to detect and identify the DoS attacker in its wireless coverage area. We applied the protocol to two Physical Layer technologies: Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) and the results are presented to validate the algorithm.

  13. Electrodeposición de nanohilos magnéticos: aleaciones de FeNi y óxidos de hierro y de cobalto

    OpenAIRE

    Llavona Serrano, Ángel

    2013-01-01

    El principal objetivo del trabajo de esta tesis doctoral ha sido la fabricación de nanohilos con diferentes aplicaciones tecnológicas mediante electrodeposición dentro de los poros de membranas de policarbonato, el estudio de los procesos de crecimiento y el estudio de sus propiedades estructurales, magnéticas y luminiscentes.

  14. A Novel Energy Saving Algorithm with Frame Response Delay Constraint in IEEE 802.16e

    Science.gov (United States)

    Nga, Dinh Thi Thuy; Kim, Mingon; Kang, Minho

    Sleep-mode operation of a Mobile Subscriber Station (MSS) in IEEE 802.16e effectively saves energy consumption; however, it induces frame response delay. In this letter, we propose an algorithm to quickly find the optimal value of the final sleep interval in sleep-mode in order to minimize energy consumption with respect to a given frame response delay constraint. The validations of our proposed algorithm through analytical results and simulation results suggest that our algorithm provide a potential guidance to energy saving.

  15. A Secure Simplification of the PKMv2 Protocol in IEEE 802.16e-2005

    DEFF Research Database (Denmark)

    Yuksel, Ender; Nielson, Hanne Riis; Nielsen, Christoffer Rosenkilde

    2007-01-01

    Static analysis is successfully used for automatically validating security properties of classical cryptographic protocols. In this paper, we shall employ the same technique to a modern security protocol for wireless networks, namely the latest version of the Privacy and Key Management protocol...... for IEEE 802.16e, PKMv2. This protocol seems to have an exaggerated mixture of security features. Thus, we iteratively investigate which components are necessary for upholding the security properties and which can be omitted safely. This approach is based on the LySa process calculus and employs...

  16. An IEEE 802.3 Compatible Real Time Medium Access Control with Length-based Priority

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new medium access control method is proposed over the predominant Ethernet broadcast channel. Taking advantages of intrinsic variable length characteristic of standard Ethernet frame, message-oriented dynamic priority mechanism is established. Prioritized medium access control operates under a so-called block mode in event of collisions.High priority messages have a chance to preempt block status incurred by low priority ones. By this means, the new MAC provides a conditional deterministic real time performance beyond a statistical one. Experiments demonstrate effectiveness and attractiveness of the proposed scheme. Moreover, this new MAC is completely compatible with IEEE802.3.

  17. 2012 Special NSREC Issue of the IEEE Transactions on Nuclear Science Comments by the Editors

    Science.gov (United States)

    Schwank, Jim; Brown, Dennis; Girard, Sylvain; Gouker, Pascale; Gerardin, Simone; Quinn, Heather; Barnaby, Hugh

    2012-12-01

    The December 2012 special issue of the IEEE Transactions on Nuclear Science contains selected papers from the 49th annual IEEE International Nuclear and Space Radiation Effects Conference (NSREC) held July 16-20, 2012, in Miami, Florida USA. 95 papers presented at the 2012 NSREC were submitted for consideration for this year’s special issue. Those papers that appear in this special issue were able to successfully complete the review process before the deadline for the December issue. A few additional papers may appear in subsequent issues of the TRANSACTIONS. This publication is the premier archival journal for research on space and nuclear radiation effects in materials, devices, circuits, and systems. This distinction is the direct result of the conscientious efforts of both the authors, who present and document their work, and the reviewers, who selflessly volunteer their time and talent to help review the manuscripts. Each paper in this journal has been reviewed by experts selected by the editors for their expertise and knowledge of the particular subject areas. The peer review process for a typical technical journal generally takes six months to one year to complete. To publish this special issue of the IEEE Transactions on Nuclear Science (in December), the review process, from initial submission to final form, must be completed in about 10 weeks. Because of the short schedule, both the authors and reviewers are required to respond very quickly. The reviewers listed on the following pages contributed vitally to this quick-turn review process.We would like to express our sincere appreciation to each of them for accepting this difficult, but critical role in the process. To provide consistent reviews of papers throughout the year, the IEEE Transactions on Nuclear Science relies on a year-round editorial board that manages reviews for submissions throughout the year to the TRANSACTIONS in the area of radiation effects. The review process is managed by a Senior

  18. A time-based admission control mechanism for IEEE 802.11 ad Hoc networks

    OpenAIRE

    Costa, Luís Henrique M. K.; Cerveira, Carlos Rodrigo

    2006-01-01

    This paper presents a time-based admission control mechanism (TAC) for IEEE 802.11 ad hoc networks. The proposed mechanism was adapted to the QoS AODV routing protocol, which takes the quality of service requirements of the data flow into account in the route discovery process. TAC-AODV estimates the idle time of the physical medium based on the frames listened. The incoming traffic is admitted according to the offered load as well as the intra-flow interference, calculated based on the numbe...

  19. 4th IEEE/ACIS International Conference on Computer and Information Science

    CERN Document Server

    2016-01-01

    This edited book presents scientific results of the 14th IEEE/ACIS International Conference on Computer and Information Science (ICIS 2015) which was held on June 28 – July 1, 2015 in Las Vegas, USA. The aim of this conference was to bring together researchers and scientists, businessmen and entrepreneurs, teachers, engineers, computer users, and students to discuss the numerous fields of computer science and to share their experiences and exchange new ideas and information in a meaningful way. Research results about all aspects (theory, applications and tools) of computer and information science, and to discuss the practical challenges encountered along the way and the solutions adopted to solve them.

  20. Impacto de mecanismos de seguridad en sensores IEEE 802.15.4

    OpenAIRE

    Tripp Barba, Carolina; Casademont Serra, Jordi

    2009-01-01

    En la actualidad son muchos los mecanismos de seguridad que el estándar IEEE 802.15.4 permite a las redes inalámbricas de sensores [1] Dicho estándar define las especificaciones de la Capa de Acceso al Medio y la Capa Física de los dispositivos inalámbricos de área personal. La última revisión corresponde al 2006. Dichas revisiones y actualizaciones son hechas por el grupo de trabajo 802.15. Sin embargo estos mecanismos consumen recursos como memoria y batería, que son...

  1. Low-frequency electrical dosimetry: research agenda of the IEEE International Committee on Electromagnetic Safety.

    Science.gov (United States)

    Reilly, J Patrick; Hirata, Akimasa

    2016-06-21

    This article treats unsettled issues in the use of numerical models of electrical dosimetry as applied to international limits on human exposure to low-frequency (typically  IEEE-ICES (International Committee on Electromagnetic Safety) Technical Committee 95. The paper discusses 25 issues needing attention, fitting into three general categories: induction models; electrostimulation models; and human exposure limits. Of these, 9 were voted as 'high priority' by members of Subcommittee 6. The list is presented as a research agenda for refinements in numerical modeling with applications to human exposure limits. It is likely that such issues are also important in medical and electrical product safety design applications.

  2. Connectivity-Based Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs

    Directory of Open Access Journals (Sweden)

    Woo-Yong Choi

    2009-01-01

    Full Text Available We propose the efficient reliable multicast MAC protocol based on the connectivity information among the recipients. Enhancing the BMMM (Batch Mode Multicast MAC protocol, the reliable multicast MAC protocol significantly reduces the RAK (Request for ACK frame transmissions in a reasonable computational time and enhances the MAC performance. By the analytical performance analysis, the throughputs of the BMMM protocol and our proposed MAC protocol are derived. Numerical examples show that our proposed MAC protocol increases the reliable multicast MAC performance for IEEE 802.11 wireless LANs.

  3. Impact of cell load on 5GHz IEEE 802.11 WLAN

    OpenAIRE

    Abu-Tair, Mamoun; Bhatti, Saleem Noel

    2017-01-01

    We have conducted an empirical study of the latest 5GHz IEEE 802.11 wireless LAN (WLAN) variants of 802.11n (5GHz) and 802.11ac (Wave 1), under different cell load conditions. We have considered typical configurations of both protocols on a Linux testbed. Under light load,there is no clear difference between 802.11n and 802.11ac in terms of performance and energy consumption. However, in some cases of high cell load, we have found that there may be a small advantage with 802.11ac. Overall, we...

  4. Distributed Fair Access Point Selection for Multi-Rate IEEE 802.11 WLANs

    Science.gov (United States)

    Gong, Huazhi; Nahm, Kitae; Kim, Jongwon

    In IEEE 802.11 networks, the access point (AP) selection based on the strongest signal strength often results in the extremely unfair bandwidth allocation among mobile users (MUs). In this paper, we propose a distributed AP selection algorithm to achieve a fair bandwidth allocation for MUs. The proposed algorithm gradually balances the AP loads based on max-min fairness for the available multiple bit rate choices in a distributed manner. We analyze the stability and overhead of the proposed algorithm, and show the improvement of the fairness via computer simulation.

  5. Rate Adaptation Based on Collision Probability for IEEE 802.11 WLANs

    Science.gov (United States)

    Kim, Taejoon; Lim, Jong-Tae

    Nowadays IEEE 802.11 wireless local area networks (WLANs) support multiple transmission rates. To achieve the best performance, transmitting stations adopt the various forms of automatic rate fallback (ARF). However, ARF suffers from severe performance degradation as the number of transmitting stations increases. In this paper, we propose a new rate adaptation scheme which adjusts the ARF's up/down threshold according to the channel contention level. Simulation result shows that the proposed scheme achieves fairly good performance compared with the existing schemes.

  6. Adaptive rate selection scheme for video transmission to resolve IEEE 802.11 performance anomaly

    Science.gov (United States)

    Tang, Guijin; Zhu, Xiuchang

    2011-10-01

    Multi-rate transmission may lead to performance anomaly in an IEEE 802.11 network. It will decrease the throughputs of all the higher rate stations. This paper proposes an adaptive rate selection scheme for video service when performance anomaly occurs. Considering that video has the characteristic of tolerance to packet loss, we actively drop several packets so as to select the rates as high as possible for transmitting packets. Experiment shows our algorithm can decrease the delay and jitter of video, and improve the system throughput as well.

  7. A Fair Cooperative MAC Protocol in IEEE 802.11 WLAN

    Directory of Open Access Journals (Sweden)

    Seyed Davoud Mousavi

    2018-05-01

    Full Text Available Cooperative communication techniques have recently enabled wireless technologies to overcome their challenges. The main objective of these techniques is to improve resource allocation. In this paper, we propose a new protocol in medium access control (MAC of the IEEE 802.11 standard. In our new protocol, which is called Fair Cooperative MAC (FC-MAC, every relay node participates in cooperation proportionally to its provided cooperation gain. This technique improves network resource allocation by exploiting the potential capacity of all relay candidates. Simulation results demonstrate that the FC-MAC protocol presents better performance in terms of throughput, fairness, and network lifetime.

  8. Latency and Jitter Analysis for IEEE 802.11e Wireless LANs

    Directory of Open Access Journals (Sweden)

    Sungkwan Youm

    2013-01-01

    Full Text Available This paper presents a numerical analysis of latency and jitter for IEEE 802.11e wireless local area networks (WLANs in a saturation condition, by using a Markov model. We use this model to explicate how the enhanced distributed coordination function (EDCF differentiates classes of service and to characterize the probability distribution of the medium access control (MAC layer packet latency and jitter, on which the quality of the voice over Internet protocol (VoIP calls is dependent. From the proposed analytic model, we can estimate the available number of nodes determining the system performance, in order to satisfy user demands on the latency and jitter.

  9. Planning of Efficient Wireless Access with IEEE 802.16 for Connecting Home Network to the Internet

    Directory of Open Access Journals (Sweden)

    Pichet Ritthisoonthorn

    2010-01-01

    Full Text Available The emergence of IEEE802.16 wireless standard technology (WiMAX has significantly increased the choice to operators for the provisioning of wireless broadband access network. WiMAX is being deployed to compliment with xDSL in underserved or lack of the broadband network area, in both developed and developing countries. Many incumbent operators in developing countries are considering the deployment of WiMAX as part of their broadband access strategy. This paper presents an efficient and simple method for planning of broadband fixed wireless access (BFWA with IEEE802.16 standard to support home connection to Internet. The study formulates the framework for planning both coverage and capacity designs. The relationship between coverage area and access rate from subscriber in each environment area is presented. The study also presents the throughput and channel capacity of IEEE802.16 in different access rates. An extensive analysis is performed and the results are applied to the real case study to demonstrate the practicality of using IEEE 802.16 for connecting home to Internet. Using empirical data and original subscriber traffic from measurement, it is shown that the BFWA with IEEE802.16 standard is a capacity limited system. The capacity of IEEE802.16 is related to different factors including frequency bandwidth, spectrum allocation, estimation of traffic per subscriber, and choice of adaptive modulation from subscriber terminal. The wireless access methods and procedures evolved in this research work and set out in this paper are shown to be well suited for planning BFWA system based on IEEE802.16 which supports broadband home to Internet connections.

  10. NRC Information No. 90-41: Potential failure of General Electric Magne-Blast circuit breakers and AK circuit breakers

    International Nuclear Information System (INIS)

    Rossi, C.E.

    1992-01-01

    This information notice is intended to alert addressees to potential safety concerns that may result from failures of GE vertical lift (AM) and horizontal draw-out (AMH) Magne-Blast circuit breakers utilizing ML-13 operating mechanisms to open or close them and AK circuit breakers. The particular breaker failures reported herein were caused by operating problems with prop springs, snap rings and lubricating grease. GE Nuclear Energy has informed the NRC that it is aware of these problems and that GE routinely checks and corrects them if the circuit breakers are serviced at one of the four GE nuclear service centers in the US. However, the NRC is aware that some utilities may have their circuit breakers repaired or serviced at facilities other than the four GE nuclear service centers

  11. Diagrama de fases temperatura-campo magnético de cadeias quânticas ferrimagnéticas

    OpenAIRE

    SILVA, Wellington Moreira da

    2015-01-01

    O trabalho consiste no estudo de cadeias quânticas ferrimagnéticas associadas a compostos ferrimagnéticos quase-unidimensionais de spins mistos s − S, com s = 1/2 e S = 1. Estudamos as fases induzidas pela aplicação de um campo magnético, B, e efeitos de temperatura, T; em particular as excitações de baixa energia e as curvas de magnetização em função de B. A modelagem teórica e realizada através do hamiltoniano de Heisenberg com acoplamentos de superexchange antiferromagnéticos, J, entre sít...

  12. Ressonância magnética na esclerose múltipla: análise de 270 casos

    Directory of Open Access Journals (Sweden)

    Minguetti Guilberto

    2001-01-01

    Full Text Available O autor apresenta 270 casos de pacientes com história clínica e imagens de ressonância magnética compatíveis com esclerose múltipla. São feitas considerações sobre a incidência quanto ao sexo, grupos etários e localização das lesões. Por se tratar de doença considerada rara nos países tropicais, o autor tece considerações didáticas sobre os critérios clínicos e de imagem úteis na prática radiológica e alerta os neurologistas para o significado desta doença na capital (Curitiba de um estado brasileiro (Paraná situado entre os paralelos 22º e 30º Sul.

  13. Processamento de imagens BOLD de ressonância magnética do músculo

    OpenAIRE

    Pereira, Ana Rita Lindo dos Santos Justo

    2012-01-01

    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção de Grau de Mestre em Engenharia Biomédica A presente dissertação foi desenvolvida com a colaboração da Faculdade de Motricidade Humana (FMH/UTL) e a Clínica de Ressonância Magnética de Caselas. A presente dissertação de mestrado pretende avaliar as alterações fisiológicas de vários músculos da perna quando submetidos a exercício físico intenso, através da técnica de resson...

  14. Modélisation du champ magnétique d'un propulseur M.H.D. annulaire

    Science.gov (United States)

    Kom, C. H.; Brunet, Y.

    1995-01-01

    Stray fields have to be as small as possible to reduce the magnetic signature of the vessel in M.H.D. propulsion where the magnetic field has to be very high. The calculation of the magnetic field of an angular M.H.D. thruster is presented. The field is produced by a distribution of superconducting magnets in the shape of sectors. An analytical formulation of the field can be used in the active zone, outside the coil ends. An analytical method using a Fourier development of the current sheets is employed for an inductor in cylindrical sectors, and a direct method is used for a massive inductor. Numerical and analytical results are compared. Pour des raisons de discrétion, les champs de fuite doivent être minimisés en propulsion M.H.D. où les champs magnétiques doivent être intenses. Le calcul du champ magnétique d'un propulseur M.H.D. naval annulaire, constitué de secteurs inducteurs supraconducteurs est représenté. Dans la zone active, hors des têtes de bobines, une formulation analytique peut être utilisée. Une méthode analytique utilisant le développemment en série de Fourier du courant est adoptée pour les industeurs cylindriques, et une méthode directe pour les inducteurs massifs. Les résultats numériques sont comparés à ceux obtenus avec un logiciel d'éléments finis 2D.

  15. Propiedades estructurales y magnéticas de aleaciones Gd0.257 -xTbxFe0.743 obtenidas por aleamiento mecánico

    Directory of Open Access Journals (Sweden)

    Mauricio Galvis-Patiño

    2017-01-01

    Full Text Available En el presente trabajo se reporta el estudio de las propiedades estructurales y magnéticas de la composición en forma de polvo de Gd0.257-xTbxFe0.743 con x=0,  0.1285,  0.257,preparados por Aleamiento Mecánico (AM en atmosfera de argón durante 72 horas mediante un molino planetario de alta energía ;la caracterización estructural se realizó por medio de Difractometría de rayos X(DRX, para la caracterización magnética se utilizó la espectroscopía Mössbauer, los ciclos de histéresis se llevaron a cabo a través de  PPMS (Physical Property Measurement System, Sistema de Medidas de Propiedades Físicas. La fase de α-Fe se presenta en los tres difractogramas mediante un pico característico cuya  intensidad disminuye al reemplazar el Tb por el Gd, presentándose la menor en x= 0 así mismo se observa un aumento de su ancho atribuible a la presencia de átomos de Gd en lugares propios del Fe. Los espectros Mössbauer (EM fueron ajustados con sextetos, dobletes, singletes y distribuciones de campo hiperfino lo que señala que el orden magnético se ve alterado al sustituir el Tb por el Gd en la composición. Las propiedades magnéticas extrínsecas de la composición en estudio, la caracterizan como materiales magnéticamente semiduros.

  16. Suscetibilidade magnética do solo e estimação da capacidade de suporte à aplicação de vinhaça

    Directory of Open Access Journals (Sweden)

    Rafael Gonçalves Peluco

    2013-06-01

    Full Text Available O objetivo deste trabalho foi avaliar a eficiência da suscetibilidade magnética do solo para estimar a capacidade de suporte de áreas à aplicação de vinhaça. Foram coletadas 241 amostras de solo, de uma área de 380 ha, nas quais foram determinados os atributos químicos, os teores de argila e a suscetibilidade magnética do solo. Foram calculadas as doses de vinhaça recomendadas para cada amostra. Os dados foram submetidos à análise estatística descritiva, e foram desenvolvidos modelos de regressão entre a suscetibilidade magnética e os outros atributos avaliados. A análise da dependência espacial dos dados foi feita com uso da geoestatística. Foram construídos mapas de krigagem e variogramas cruzados, para averiguar a correlação espacial entre a suscetibilidade magnética e os atributos estudados. Com base no mapa de recomendação de vinhaça, nas classes de solo e nos mapas de krigagem, foram calculadas as doses médias de vinhaça e as capacidades de suporte médias, ponderadas pela área. A suscetibilidade magnética apresenta correlação espacial linear significativa com as doses de vinhaça recomendadas e com a capacidade de suporte do solo à aplicação desse efluente, e pode ser utilizada como componente da função de pedotransferência, na quantificação indireta da capacidade de suporte.

  17. Trans-sphenoidal excision of craniopharyngiomas.

    Directory of Open Access Journals (Sweden)

    Nagpal R

    1991-04-01

    Full Text Available Craniopharyngiomas have been by and large excised by the transcranial route. Since 1982, 11 patients have been operated by the traus-sphensidal route in the department. The clinical features with which they were presented, diagnostic investigations, details of surgical procedures and follow-up analysis is being presented here. A retrospective study of radiological investigation was done to determine the features that help decide the choice of surgical approach to these lesions. Only lesions that were primarily intrasellar, cystic and those that expanded the sella could be treated by the trans-sphenoidal route. Associated suprasellar extensions could also be removed. Predominantly calcified or firm, fleshy tumours lent themselves poorly to removal by the trans-sphenoidal route.

  18. Trans Fat Bans and Human Freedom

    Science.gov (United States)

    Resnik, David

    2014-01-01

    A growing body of evidence has linked consumption of trans fatty acids to cardiovascular disease. To promote public health, numerous state and local governments in the United States have banned the use of artificial trans fats in restaurant foods, and additional bans may follow. Although these policies may have a positive impact on human health, they open the door to excessive government control over food, which could restrict dietary choices, interfere with cultural, ethnic, and religious traditions, and exacerbate socioeconomic inequalities. These slippery slope concerns cannot be dismissed as far-fetched, because the social and political pressures are place to induce additional food regulations. To protect human freedom and other values, policies that significantly restrict food choices, such as bans on types of food, should be adopted only when they are supported by substantial scientific evidence, and when policies that impose fewer restrictions on freedom, such as educational campaigns and product labeling, are likely to be ineffective. PMID:20229412

  19. Introduction to Trans Australia Airlines CRM training

    Science.gov (United States)

    Davidson, Jim

    1987-01-01

    Trans Australia believes that its excellent accident rate record is due to a number of factors. It has a good group of standard operating procedures, and its crews are pretty well self-disciplined and adhere to those procedures. But the other thing that it believes is a factor in its safety record is that perhaps it is also due to its preparedness to be innovative, to keep up with what is going on in the rest of the world and, if it looks to have value, then to be amongst the first to try it out. Trans Australia commenced a program similar to Line Oriented Flight Training (LOFT) fairly early in 1979--that being its first windshear program-- which leads to why they are doing a course of resource management training, which we have chosen to call Aircrew Team Management (ATM). This course is detailed in another presentation.

  20. Siegel discs via trans-quasiconformal surgery

    DEFF Research Database (Denmark)

    Petersen, Carsten Lunde

    2014-01-01

    kompleksstruktur kan integreres, det vil sige definerer en kompleksstruktur. I denne komplekse struktur er den nye afbildning holomorf og har en Siegel disk. Der findes imidlertid masser af tilfælde hvor dette ikke lader sig gøre, men hvor man istedet kan finde en trans-kvasikonform udvidelse til enheds-disken af...... mængde af rotationstal med fuldt mål på cirklen har konjugationen en trans-kvasi-konform udvidelse til disken. Dette er et skridt i beviset for at for næsten alle (i Lebeguemåls forstand) rotations tal, er randen af Siegel-disken for et kvadratisk polynomium med en Siegel disk med et sådant rotationstal...

  1. Analysis of Trans Fat in Edible Oils with Cooking Process

    Science.gov (United States)

    Song, Juhee; Park, Joohyeok; Jung, Jinyeong; Lee, Chankyu; Gim, Seo Yeoung; Ka, HyeJung; Yi, BoRa; Kim, Mi-Ja; Kim, Cho-il

    2015-01-01

    Trans fat is a unsaturated fatty acid with trans configuration and separated double bonds. Analytical methods have been introduced to analyze trans fat content in foods including infrared (IR) spectroscopy, gas chromatography (GC), Fourier transform-infrared (FT-IR) spectroscopy, reverses-phase silver ion high performance liquid chromatography, and silver nitrate thin layer chromatography. Currently, FT-IR spectroscopy and GC are mostly used methods. Trans fat content in 6 vegetable oils were analyzed and processing effects including baking, stir-frying, pan-frying, and frying on the formation of trans fat in corn oil was evaluated by GC. Among tested vegetable oils, corn oil has 0.25 g trans fat/100 g, whereas other oils including rapeseed, soybean, olive, perilla, and sesame oils did not have detectable amount of trans fat content. Among cooking methods, stir-frying increased trans fat in corn oil whereas baking, pan-frying, and frying procedures did not make changes in trans fat content compared to untreated corn oils. However, the trans fat content was so low and food label can be declared as ‘0’ trans based on the regulation of Ministry of Food ad Drug Safety (MFDS) (edible oil). PMID:26483890

  2. Trans-triquetral Perilunate fracture dislocation

    OpenAIRE

    John-Henry Rhind; Abhinav Gulihar; Andrew Smith

    2018-01-01

    Perilunate dislocations and perilunate fracture dislocations are rare and serious injuries. Perilunate dislocations represent less than 10% of all carpal injuries of which 61% represent transcaphoid fractures. Because of their rarity, up to 25% of perilunate dislocations are initially missed on first assessment. We present the case of a 66-year-old-gentleman who sustained an isolated trans-triquetral perilunate fracture dislocation while walking his dog. This was diagnosed in the emergency de...

  3. A strategy for implementation of experience based seismic equipment qualification in IEEE and ASME industry standards

    International Nuclear Information System (INIS)

    Adams, T.M.

    1996-01-01

    In the past 20 years, extensive data on the performance of mechanical and electric equipment during actual strong motion earthquakes and seismic qualification tests has been accumulated. Recognizing that an experience based approach provides a technically sound and cost effective method for the seismic qualification of some or certain equipment, the IEEE Nuclear Power Engineering Committee and the ASME Committee on Qualification of Mechanical Equipment established a Special Working Group to investigate the incorporation of experienced based methods into the industry consensus codes and standards currently used in the seismic qualification of Seismic Category Nuclear Power Plant equipment. This paper presents the strategy (course of action) which was developed by the Special Working Group for meeting this objective of incorporation of experience based seismic qualification standards used in the design and seismic qualification of seismic category nuclear power plant equipment. This strategy was recommended to both chartering organizations, the IEEE Nuclear Power Engineering Committee and the ASME Committee on Qualification of Mechanical Equipment for their consideration and implementation. The status of the review and implementation of the Special Working Group's recommended strategy by the sponsoring organization is also discussed

  4. 2008 Special NSREC Issue of the IEEE Transactions on Nuclear Science Comments by the Editors

    Science.gov (United States)

    Schwank, Jim; Buchner, Steve; Marshall, Paul; Duzellier, Sophie; Brown, Dennis; Poivey, Christian; Pease, Ron

    2008-12-01

    The December 2008 special issue of the IEEE Transactions on Nuclear Science contains selected papers from the 45th annual IEEE International Nuclear and Space Radiation Effects Conference (NSREC) held in Tucson, Arizona, July 14 - 18, 2008. Over 115 papers presented at the 2008 NSREC were submitted for consideration for this year's special issue. Those papers that appear in this special issue were able to successfully complete the review process before the deadline for the December issue. A few additional papers may appear in subsequent issues of the TRANSACTIONS. This publication is the premier archival journal for research on space and nuclear radiation effects in materials, devices, circuits, and systems. This distinction is the direct result of the conscientious efforts of both the authors, who present and document their work, and the reviewers, who selflessly volunteer their time and talent to help review the manuscripts. Each paper in this journal has been reviewed by experts selected by the editors for their expertise and knowledge of the particular subject areas.

  5. BOB-RED queue management for IEEE 802.15.4 wireless sensor networks

    Directory of Open Access Journals (Sweden)

    Wu Jean-Lien

    2011-01-01

    Full Text Available Abstract Multimedia services over resource constrained wireless sensor networks (WSNs face a performance bottleneck issue from the gateway node to the sink node. Therefore, the queue management at the gateway node is crucial for diversified messages conveyed from the front nodes to the sink node. In this article, beacon order-based random early detection (BOB-RED queue management is proposed. BOB-RED is a dynamic adaptation scheme based on adjusting beacon interval and superframe duration in the IEEE 802.15.4 MAC superframe accompanied with RED queue management scheme to increase the transmission efficiency of multimedia over WSNs. We focus on the performance improvement upon different traffic loads over WSNs. Evaluation metrics include end-to-end delay, packet delivery ratio, and energy consumption in IEEE 802.15.4 beacon enabled mode. Simulation results show that BOB-RED can effectively decrease end-to-end delay and energy consumption compared to the DropTail scheme.

  6. Throughput analysis of the IEEE 802.4 token bus standard under heavy load

    Science.gov (United States)

    Pang, Joseph; Tobagi, Fouad

    1987-01-01

    It has become clear in the last few years that there is a trend towards integrated digital services. Parallel to the development of public Integrated Services Digital Network (ISDN) is service integration in the local area (e.g., a campus, a building, an aircraft). The types of services to be integrated depend very much on the specific local environment. However, applications tend to generate data traffic belonging to one of two classes. According to IEEE 802.4 terminology, the first major class of traffic is termed synchronous, such as packetized voice and data generated from other applications with real-time constraints, and the second class is called asynchronous which includes most computer data traffic such as file transfer or facsimile. The IEEE 802.4 token bus protocol which was designed to support both synchronous and asynchronous traffic is examined. The protocol is basically a timer-controlled token bus access scheme. By a suitable choice of the design parameters, it can be shown that access delay is bounded for synchronous traffic. As well, the bandwidth allocated to asynchronous traffic can be controlled. A throughput analysis of the protocol under heavy load with constant channel occupation of synchronous traffic and constant token-passing times is presented.

  7. Real-Time-Simulation of IEEE-5-Bus Network on OPAL-RT-OP4510 Simulator

    Science.gov (United States)

    Atul Bhandakkar, Anjali; Mathew, Lini, Dr.

    2018-03-01

    The Real-Time Simulator tools have high computing technologies, improved performance. They are widely used for design and improvement of electrical systems. The advancement of the software tools like MATLAB/SIMULINK with its Real-Time Workshop (RTW) and Real-Time Windows Target (RTWT), real-time simulators are used extensively in many engineering fields, such as industry, education, and research institutions. OPAL-RT-OP4510 is a Real-Time Simulator which is used in both industry and academia. In this paper, the real-time simulation of IEEE-5-Bus network is carried out by means of OPAL-RT-OP4510 with CRO and other hardware. The performance of the network is observed with the introduction of fault at various locations. The waveforms of voltage, current, active and reactive power are observed in the MATLAB simulation environment and on the CRO. Also, Load Flow Analysis (LFA) of IEEE-5-Bus network is computed using MATLAB/Simulink power-gui load flow tool.

  8. Improving Energy Efficiency in Idle Listening of IEEE 802.11 WLANs

    Directory of Open Access Journals (Sweden)

    Muhammad Adnan

    2016-01-01

    Full Text Available This paper aims to improve energy efficiency of IEEE 802.11 wireless local area networks (WLANs by effectively dealing with idle listening (IL, which is required for channel sensing and is unavoidable in a contention-based channel access mechanism. Firstly, we show that IL is a dominant source of energy drain in WLANs and it cannot be effectively alleviated by the power saving mechanism proposed in the IEEE 802.11 standard. To solve this problem, we propose an energy-efficient mechanism that combines three schemes in a systematic way: downclocking, frame aggregation, and contention window adjustment. The downclocking scheme lets a station remain in a semisleep state when overhearing frames destined to neighbor stations, whereby the station consumes the minimal energy without impairing channel access capability. As well as decreasing the channel access overhead, the frame aggregation scheme prolongs the period of semisleep time. Moreover, by controlling the size of contention window based on the number of stations, the proposed mechanism decreases unnecessary IL time due to collision and retransmission. By deriving an analysis model and performing extensive simulations, we confirm that the proposed mechanism significantly improves the energy efficiency and throughput, by up to 2.8 and 1.8 times, respectively, compared to the conventional power saving mechanisms.

  9. A Green Media Access Method for IEEE 802.15.6 Wireless Body Area Network.

    Science.gov (United States)

    Jacob, Anil K; Jacob, Lillykutty

    2017-09-30

    It is of utmost importance to conserve battery energy to the maximum possible extent in WBAN nodes while collecting and transferring medical data. The IEEE 802.15.6 WBAN standard does not specify any method to conserve energy. This paper focuses on a method to conserve energy in IEEE 802.15.6 WBAN nodes when using CSMA/CA, while simultaneously restricting data delivery delay to the required value as specified in medical applications. The technique is to allow the nodes to sleep all the times except for receiving beacons and for transmitting data frames whenever a data frame enters an empty buffer. The energy consumed by the nodes and the average latency of data frame for periodical arrival of data are found out analytically. The analytical results are validated and also the proposed method is compared with other energy conserving schemes, using Castalia simulation studies. The proposed method shows superior performance in both device lifetime and latency of emergency medical data.

  10. Predictable and reliable ECG monitoring over IEEE 802.11 WLANs within a hospital.

    Science.gov (United States)

    Park, Juyoung; Kang, Kyungtae

    2014-09-01

    Telecardiology provides mobility for patients who require constant electrocardiogram (ECG) monitoring. However, its safety is dependent on the predictability and robustness of data delivery, which must overcome errors in the wireless channel through which the ECG data are transmitted. We report here a framework that can be used to gauge the applicability of IEEE 802.11 wireless local area network (WLAN) technology to ECG monitoring systems in terms of delay constraints and transmission reliability. For this purpose, a medical-grade WLAN architecture achieved predictable delay through the combination of a medium access control mechanism based on the point coordination function provided by IEEE 802.11 and an error control scheme based on Reed-Solomon coding and block interleaving. The size of the jitter buffer needed was determined by this architecture to avoid service dropout caused by buffer underrun, through analysis of variations in transmission delay. Finally, we assessed this architecture in terms of service latency and reliability by modeling the transmission of uncompressed two-lead electrocardiogram data from the MIT-BIH Arrhythmia Database and highlight the applicability of this wireless technology to telecardiology.

  11. Investigating the efficiency of IEEE 802.15.4 for medical monitoring applications.

    Science.gov (United States)

    Pelegris, P; Banitsas, K

    2011-01-01

    Recent advancements in wireless communications technologies bring us one step closer to provide reliable Telecare services as an alternative to patients staying in a hospital mainly for monitoring purposes. In this research we investigate the efficiency of IEEE 802.15.4 in a simple scenario where a patient is being monitored using an ECG and a blood analysis module. This approach binds well with assisted living solutions, by sharing the network infrastructure for both monitoring and control while taking advantage of the low power features of the protocol. Such applications are becoming more and more realistic to implement as IEEE 802.15.4 compatible hardware becomes increasingly available. Our aim is to examine the impact of Beacon and Superframe Order in the medium access delay, dropped packets, end to end delay, average retransmission attempts and consumed power focusing on this bandwidth demanding situation where the network load does not allow low duty cycles, in order to draw some conclusions on the effect that this will have to telemonitoring applications.

  12. Self-Coexistence among IEEE 802.22 Networks: Distributed Allocation of Power and Channel.

    Science.gov (United States)

    Sakin, Sayef Azad; Razzaque, Md Abdur; Hassan, Mohammad Mehedi; Alamri, Atif; Tran, Nguyen H; Fortino, Giancarlo

    2017-12-07

    Ensuring self-coexistence among IEEE 802.22 networks is a challenging problem owing to opportunistic access of incumbent-free radio resources by users in co-located networks. In this study, we propose a fully-distributed non-cooperative approach to ensure self-coexistence in downlink channels of IEEE 802.22 networks. We formulate the self-coexistence problem as a mixed-integer non-linear optimization problem for maximizing the network data rate, which is an NP-hard one. This work explores a sub-optimal solution by dividing the optimization problem into downlink channel allocation and power assignment sub-problems. Considering fairness, quality of service and minimum interference for customer-premises-equipment, we also develop a greedy algorithm for channel allocation and a non-cooperative game-theoretic framework for near-optimal power allocation. The base stations of networks are treated as players in a game, where they try to increase spectrum utilization by controlling power and reaching a Nash equilibrium point. We further develop a utility function for the game to increase the data rate by minimizing the transmission power and, subsequently, the interference from neighboring networks. A theoretical proof of the uniqueness and existence of the Nash equilibrium has been presented. Performance improvements in terms of data-rate with a degree of fairness compared to a cooperative branch-and-bound-based algorithm and a non-cooperative greedy approach have been shown through simulation studies.

  13. Performance analysis of the IEEE 802.16e power management for the initiations of awakening

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To increase battery life in IEEE 802.16e systems, it is essential to efficiently manage energy in mobile stations. The sleep-mode operation in power management helps to increase the life of a station by saving energy consumption. In power management, there are two important performance metrics: energy consumption and the response delay of awakening medium access control (MAC) service data unit (SDU). While in a base station (BS) initiation of awakening, the two performance metrics should be simultaneously considered, in a mobile subscriber station (MSS) initiation of awakening, the response delay is not considered because it is self-operational. There performance metrics are affected by the minimum sleep interval (Tmin), the maximum sleep interval (Tmax), and the average interarrival time of awakening MAC SDUs (TI) during sleep-mode operation. Therefore, it is imperative to evaluate the two initiations of awakening depending on TI. To reach a fuller understanding of the performance, this paper shows an analytical mode and simulations results for the standard sleep-mode operation in the IEEE 802.16e MAC.

  14. IEEE 1394 CAMERA IMAGING SYSTEM FOR BROOKHAVENS BOOSTER APPLICATION FACILITY BEAM DIAGNOSTICS

    International Nuclear Information System (INIS)

    BROWN, K.A.; FRAK, B.; GASSNER, D.; HOFF, L.; OLSEN, R.H.; SATOGATA, T.; TEPIKIAN, S.

    2002-01-01

    Brookhaven's Booster Applications Facility (BAF) will deliver resonant extracted heavy ion beams from the AGS Booster to short-exposure fixed-target experiments located at the end of the BAF beam line. The facility is designed to deliver a wide range of heavy ion species over a range of intensities from 10 3 to over 10 8 ions/pulse, and over a range of energies from 0.1 to 3.0 GeV/nucleon. With these constraints we have designed instrumentation packages which can deliver the maximum amount of dynamic range at a reasonable cost. Through the use of high quality optics systems and neutral density light filters we will achieve 4 to 5 orders of magnitude in light collection. By using digital IEEE1394 camera systems we are able to eliminate the frame-grabber stage in processing and directly transfer data at maximum rates of 400 Mb/set. In this note we give a detailed description of the system design and discuss the parameters used to develop the system specifications. We will also discuss the IEEE1394 camera software interface and the high-level user interface

  15. An Adaptive Medium Access Parameter Prediction Scheme for IEEE 802.11 Real-Time Applications

    Directory of Open Access Journals (Sweden)

    Estefanía Coronado

    2017-01-01

    Full Text Available Multimedia communications have experienced an unprecedented growth due mainly to the increase in the content quality and the emergence of smart devices. The demand for these contents is tending towards wireless technologies. However, these transmissions are quite sensitive to network delays. Therefore, ensuring an optimum QoS level becomes of great importance. The IEEE 802.11e amendment was released to address the lack of QoS capabilities in the original IEEE 802.11 standard. Accordingly, the Enhanced Distributed Channel Access (EDCA function was introduced, allowing it to differentiate traffic streams through a group of Medium Access Control (MAC parameters. Although EDCA recommends a default configuration for these parameters, it has been proved that it is not optimum in many scenarios. In this work a dynamic prediction scheme for these parameters is presented. This approach ensures an appropriate traffic differentiation while maintaining compatibility with the stations without QoS support. As the APs are the only devices that use this algorithm, no changes are required to current network cards. The results show improvements in both voice and video transmissions, as well as in the QoS level of the network that the proposal achieves with regard to EDCA.

  16. Dynamic Contention Window Control Scheme in IEEE 802.11e EDCA-Based Wireless LANs

    Science.gov (United States)

    Abeysekera, B. A. Hirantha Sithira; Matsuda, Takahiro; Takine, Tetsuya

    In the IEEE 802.11 MAC protocol, access points (APs) are given the same priority as wireless terminals in terms of acquiring the wireless link, even though they aggregate several downlink flows. This feature leads to a serious throughput degradation of downlink flows, compared with uplink flows. In this paper, we propose a dynamic contention window control scheme for the IEEE 802.11e EDCA-based wireless LANs, in order to achieve fairness between uplink and downlink TCP flows while guaranteeing QoS requirements for real-time traffic. The proposed scheme first determines the minimum contention window size in the best-effort access category at APs, based on the number of TCP flows. It then determines the minimum and maximum contention window sizes in higher priority access categories, such as voice and video, so as to guarantee QoS requirements for these real-time traffic. Note that the proposed scheme does not require any modification to the MAC protocol at wireless terminals. Through simulation experiments, we show the effectiveness of the proposed scheme.

  17. Adaptive Backoff Algorithm for Contention Window for Dense IEEE 802.11 WLANs

    Directory of Open Access Journals (Sweden)

    Ikram Syed

    2016-01-01

    Full Text Available The performance improvement in IEEE 802.11 WLANs in widely fluctuating network loads is a challenging task. To improve the performance in this saturated state, we develop an adaptive backoff algorithm that maximizes the system throughput, reduces the collision probability, and maintains a high fairness for the IEEE 802.11 DCF under dense network conditions. In this paper, we present two main advantages of the proposed ABA-CW algorithm. First, it estimates the number of active stations and then calculates an optimal contention window based on the active station number. Each station calculates the channel state probabilities by observing the channel for the total backoff period. Based on these channel states probabilities, each station can estimate the number of active stations in the network, after which it calculates the optimal CW utilizing the estimated active number of stations. To evaluate the proposed mechanism, we derive an analytical model to determine the network performance. From our results, the proposed ABA-CW mechanism achieved better system performance compared to fixed-CW (BEB, EIED, LILD, and SETL and adaptive-CW (AMOCW, Idle Sense mechanisms. The simulation results confirmed the outstanding performance of the proposed mechanism in that it led to a lower collision probability, higher throughput, and high fairness.

  18. Self-Coexistence among IEEE 802.22 Networks: Distributed Allocation of Power and Channel

    Directory of Open Access Journals (Sweden)

    Sayef Azad Sakin

    2017-12-01

    Full Text Available Ensuring self-coexistence among IEEE 802.22 networks is a challenging problem owing to opportunistic access of incumbent-free radio resources by users in co-located networks. In this study, we propose a fully-distributed non-cooperative approach to ensure self-coexistence in downlink channels of IEEE 802.22 networks. We formulate the self-coexistence problem as a mixed-integer non-linear optimization problem for maximizing the network data rate, which is an NP-hard one. This work explores a sub-optimal solution by dividing the optimization problem into downlink channel allocation and power assignment sub-problems. Considering fairness, quality of service and minimum interference for customer-premises-equipment, we also develop a greedy algorithm for channel allocation and a non-cooperative game-theoretic framework for near-optimal power allocation. The base stations of networks are treated as players in a game, where they try to increase spectrum utilization by controlling power and reaching a Nash equilibrium point. We further develop a utility function for the game to increase the data rate by minimizing the transmission power and, subsequently, the interference from neighboring networks. A theoretical proof of the uniqueness and existence of the Nash equilibrium has been presented. Performance improvements in terms of data-rate with a degree of fairness compared to a cooperative branch-and-bound-based algorithm and a non-cooperative greedy approach have been shown through simulation studies.

  19. The TransPetro emergency response system

    Energy Technology Data Exchange (ETDEWEB)

    Filho, A.T.F.; Cardoso, V.F.; Carbone, R.; Berardinelli, R.P. [Petrobras-TransPetro, Rio de Janeiro (Brazil); Carvalho, M.T.M.; Casanova, M.A. [Pontificia Univ. Catolica, Rio de Janeiro (Brazil). Dept. de Informatica, TeCGraf

    2004-07-01

    Petrobras-TransPetro developed the TransPetro Emergency Response System in response to emergency situations at large oil pipelines or at terminal facilities located in sea or river harbour areas. The standard of excellence includes full compliance with environmental regulations set by the federal government. A distributed workflow management software called InfoPAE forms the basis of the system in which actions are defined, along with geographic and conventional data. The first prototype of InfoPAE was installed in 1999. Currently it is operational in nearly 80 installations. The basic concepts and functionality of the TransPetro Emergency Response System were outlined in this paper with reference to the mitigative actions that are based on an evaluation of the organization of the emergency teams; the communication procedures; characterization of the installations; definition of accidental scenarios; environmental sensitivity maps; simulation of oil spill trajectories and dispersion behaviour; geographical data of the area surrounding the installations; and, other conventional data related to the installations, including available equipment. The emergency response team can take action as soon as an accident is detected. The action plan involves characterizing several scenarios and delegating mitigative actions to specific sub-teams, each with access to geographic data on the region where the emergency occurred. 13 refs., 3 figs.

  20. Physics of trans-Planckian gravity

    International Nuclear Information System (INIS)

    Dvali, Gia; Folkerts, Sarah; Germani, Cristiano

    2011-01-01

    We study the field theoretical description of a generic theory of gravity flowing to Einstein general relativity in IR. We prove that, if ghost-free, in the weakly-coupled regime such a theory can never become weaker than general relativity. Using this fact, as a by-product, we suggest that in a ghost-free theory of gravity trans-Planckian propagating quantum degrees of freedom cannot exist. The only physical meaning of a trans-Planckian pole is the one of a classical state (black hole) which is described by the light IR quantum degrees of freedom and gives exponentially-suppressed contributions to virtual processes. In this picture Einstein gravity is UV self-complete, although not Wilsonian, and sub-Planckian distances are unobservable in any healthy theory of gravity. We then finally show that this UV/IR correspondence puts a severe constraint on any attempt of conventional Wilsonian UV-completion of trans-Planckian gravity. Specifically, there is no well-defined energy domain in which gravity could become asymptotically weak or safe.

  1. TransAlta 2003 annual report

    International Nuclear Information System (INIS)

    2004-01-01

    This annual report presents financial information from TransAlta Corp., along with a review of its operations throughout 2003 and a summary of the how the electric utility has performed in terms of power generation, independent power producers, transmission and energy marketing. TransAlta is one of the largest non-regulated power generation and wholesale marketing companies in Canada. It's assets include coal-fired, gas-fired, hydro and renewable generation facilities in Canada, the United States, Mexico and Australia. Reported earnings in 2003 were $1.26 per share compared to $1.17 in 2002. The strong first quarter was followed by harsh market conditions, low water levels which affected hydro production, and pricing restrictions in Ontario that reduced contribution from the Sarnia plant. This report outlines the utility's progress in increasing revenue and producing more power. In 2003, unplanned outages were reduced by 7 per cent and injury frequency rate was reduced by 27 per cent. The installation of 114 wind turbines in Fort Macleod, Alberta, increased TransAlta's renewable energy capacity to 3.7 per cent in 2003. The wind farm produces 75 MW of electricity, enough to power more than 32,500 homes annually. This report summarized the company's energy resource activities and presented an operations review as well as consolidated financial statements and common share information. This included the utility's assets, liabilities, revenues, expenses and cash flows. Revenue and expenditure statements were summarized by source. refs., tabs., figs

  2. TransCanada Corporation 2003 annual report

    International Nuclear Information System (INIS)

    2004-01-01

    This annual report presents financial information from TransCanada Corp., along with a review of its operations throughout 2003 and a summary of the how the company performed in terms of providing natural gas transmission and power services in North America. In 2003, TransCanada increased earnings from continuing operations by 7 per cent. It maintained a strong cash flow and continued to strengthen its balance sheet. More than 1.2 billion was invested and dividends were increased by 7 per cent in January 2004, for a total return to shareholders of 27 per cent, including dividends. In 2003, TransCanada also increased its ownership interest in Foothills Pipe Lines Ltd. to 100 per cent from 50 per cent. It secured a position in the Mackenzie Gas Pipeline Project and progressed the development of multiple liquefied natural gas projects in the northeast United States and eastern Canada. The company acquired 31.6 per cent interest in Bruce Power, adding nearly 1,500 megawatts base load generation to its portfolio. Plans are underway for cogeneration plants in Quebec, New Brunswick and Alberta. This report summarized the company's energy resource activities and presented an operations review as well as consolidated financial statements and common share information. This included the utility's assets, liabilities, revenues, expenses and cash flows. Revenue and expenditure statements were summarized by source. tabs., figs

  3. TransCanada Corporation 2004 annual report

    International Nuclear Information System (INIS)

    2005-01-01

    TransCanada is a leading North American energy company dealing with natural gas transmission, power generation and marketing opportunities. Financial information from TransCanada was presented in this annual report along with a review of its operations in 2004 and a summary of how the company performed in terms of providing natural gas transmission and power services in North America. In 2004, TransCanada increased earnings from continuing operations and maintained a strong cash flow and continued to strengthen its balance sheet. Achievements in 2004 included the acquisition of the Gas Transmission Northwest Pipeline System and the North Baja Pipeline System; the purchase of hydroelectric generation assets in New England with a total generating capacity of more than 500 MW; and the completed construction of two new gas-fired cogeneration plants, the 165 MW MacKay River facility in Alberta and the 90 MW Grandview facility in New Brunswick. The challenges in 2004 included the performance of the company's existing asset-based businesses and the new initiatives to produce another year of solid operating and financial results. This report summarized the company's energy resource activities and presented an operations review as well as consolidated financial statements and common share information. This included the utility's assets, liabilities, revenues, expenses and cash flows. Revenue and expenditure statements were summarized by source. tabs., figs

  4. Trans-Cultural, Trans-Language Practices: Potentialities for Rethinking Doctoral Education Pedagogies

    Directory of Open Access Journals (Sweden)

    Sarojni Choy

    2017-01-01

    Full Text Available Over the last decade, there has been a rapid increase in doctoral enrolments of Asian international students in Australian universities. While policies have been developed to meet the needs of these students, there seems to be some confusion around the terms internationalisation, globalisation, bi-cultural, inter-cultural, multi-cultural, and trans-cultural within these policies. In this paper, we define these terms and advocate for a policy position which orients to a futurist definition of culture. We then review the work of Michael Singh and his research team at Western Sydney University who have responded to this rapid increase in Asian international student doctoral enrolments in Australian universities by developing pedagogic principles around notions of trans-language and trans-cultural practices. In the final section of the paper, we then draw on our own experiences of doctoral supervision in Australian universities to reflect on our positioning within the pedagogic principles around trans-language and trans-cultural practices.

  5. An Authentication and Key Management Mechanism for Resource Constrained Devices in IEEE 802.11-based IoT Access Networks

    OpenAIRE

    Kim, Ki-Wook; Han, Youn-Hee; Min, Sung-Gi

    2017-01-01

    Many Internet of Things (IoT) services utilize an IoT access network to connect small devices with remote servers. They can share an access network with standard communication technology, such as IEEE 802.11ah. However, an authentication and key management (AKM) mechanism for resource constrained IoT devices using IEEE 802.11ah has not been proposed as yet. We therefore propose a new AKM mechanism for an IoT access network, which is based on IEEE 802.11 key management with the IEEE 802.1X aut...

  6. Problems and solutions in application of IEEE standards at Savannah River Site, Department of Energy (DOE) nuclear facilities

    International Nuclear Information System (INIS)

    Lee, Y.S.; Bowers, T.L.; Chopra, B.J.; Thompson, T.T.; Zimmerman, E.W.

    1993-01-01

    The Department of Energy (DOE) Nuclear Material Production Facilities at the Savannah River Site (SRS) were designed, constructed, and placed into operation in the early 1950's, based on existing industry codes/standards, design criteria, analytical procedures. Since that time, DOE has developed Orders and Polices for the planning, design and construction of DOE Nuclear Reactor Facilities which invoke or reference commercial nuclear reactor codes and standards. The application of IEEE reactor design requirements such as Equipment Qualification, Seismic Qualification, Single Failure Criteria, and Separation Requirement, to non-reactor facilities has been a problem since the IEEE reactor criteria do not directly confirm to the needs of non-reactor facilities. SRS Systems Engineering is developing a methodology for the application of IEEE Standards to non-reactor facilities at SRS

  7. A distributed scheme to manage the dynamic coexistence of IEEE 802.15.4-based health-monitoring WBANs.

    Science.gov (United States)

    Deylami, Mohammad N; Jovanov, Emil

    2014-01-01

    The overlap of transmission ranges between wireless networks as a result of mobility is referred to as dynamic coexistence. The interference caused by coexistence may significantly affect the performance of wireless body area networks (WBANs) where reliability is particularly critical for health monitoring applications. In this paper, we analytically study the effects of dynamic coexistence on the operation of IEEE 802.15.4-based health monitoring WBANs. The current IEEE 802.15.4 standard lacks mechanisms for effectively managing the coexistence of mobile WBANs. Considering the specific characteristics and requirements of health monitoring WBANs, we propose the dynamic coexistence management (DCM) mechanism to make IEEE 802.15.4-based WBANs able to detect and mitigate the harmful effects of coexistence. We assess the effectiveness of this scheme using extensive OPNET simulations. Our results indicate that DCM improves the successful transmission rates of dynamically coexisting WBANs by 20%-25% for typical medical monitoring applications.

  8. Simultaneous transmission of the IEEE 802.11 radio signal and optical Gbit Ethernet over the multimode fiber link

    Science.gov (United States)

    Maksymiuk, L.; Podziewski, A.

    2015-09-01

    In the paper we present a successful joint transmission of the IEEE 802.11 signal and an optical Gbit Ethernet over a multimode fiber based link. Most importantly, the multiplexation of both signals was performed in the optical domain. Due to the utilization of the multimode fiber the OBI noise was avoided and both channels were able to operate at the same wavelength. We prove that potential RoF link for IEEE 802.11 signal distribution may be used to additionally transmit other signals as Gbit Ethernet and therefore utilize the fiber infrastructure installed more effectively. The qualities of both the IEEE 802.11 and Ethernet transmissions fulfilled the requirements imposed by appropriate standards.

  9. A Cross-Layer Key Management Scheme for MIPv6 Fast Handover over IEEE 802.11 Wireless LAN

    Directory of Open Access Journals (Sweden)

    Chang-Seop Park

    2015-01-01

    Full Text Available A new key management and security scheme is proposed to integrate Layer Two (L2 and Layer Three (L3 keys for secure and fast Mobile IPv6 handover over IEEE 802.11 Wireless Local Area Network (WLAN. Unlike the original IEEE 802.11-based Mobile IPv6 Fast Handover (FMIPv6 that requires time-consuming IEEE 802.1x-based Extensible Authentication Protocol (EAP authentication on each L3 handover, the newly proposed key management and security scheme requires only one 802.1x-EAP regardless of how many L3 handovers occur. Therefore, the proposed scheme reduces the handover latency that results from a lengthy 802.1x-based EAP. The proposed key management and security scheme is extensively analyzed in terms of security and performance, and the proposed security scheme is shown to be more secure than those that were previously proposed.

  10. TransCanada PipeLines Limited 1998 annual report : TransCanada energy solutions

    International Nuclear Information System (INIS)

    1999-01-01

    Financial information from TransCanada PipeLines Limited and a review of the company's 1998 operations was made available for the benefit of shareholders. TransCanada's pipeline system transports natural gas and crude oil from Western Canada Sedimentary Basin to North America's major energy markets. Net earnings from continuing operations for 1998, before unusual charges, were $575 million ($ 355 million after unusual charges) compared to $522 million for 1997. Solid performances from the energy transmission and international business, when compared to 1997, were more than offset by a decreased contribution from energy processing. TransCanada recorded integration costs of $166 million, after tax, related to the merger with NOVA in 1998, which was the major operational accomplishment during the year, creating a seamless economic energy delivery, processing and marketing system from the wellhead to the market. tabs., figs

  11. Sexual desire in trans persons: associations with sex reassignment treatment.

    Science.gov (United States)

    Wierckx, Katrien; Elaut, Els; Van Hoorde, Birgit; Heylens, Gunter; De Cuypere, Griet; Monstrey, Stan; Weyers, Steven; Hoebeke, Piet; T'Sjoen, Guy

    2014-01-01

    Sex steroids and genital surgery are known to affect sexual desire, but little research has focused on the effects of cross-sex hormone therapy and sex reassignment surgery on sexual desire in trans persons. This study aims to explore associations between sex reassignment therapy (SRT) and sexual desire in a large cohort of trans persons. A cross-sectional single specialized center study including 214 trans women (male-to-female trans persons) and 138 trans men (female-to-male trans persons). Questionnaires assessing demographics, medical history, frequency of sexual desire, hypoactive sexual desire disorder (HSDD), and treatment satisfaction. In retrospect, 62.4% of trans women reported a decrease in sexual desire after SRT. Seventy-three percent of trans women never or rarely experienced spontaneous and responsive sexual desire. A third reported associated personal or relational distress resulting in a prevalence of HSDD of 22%. Respondents who had undergone vaginoplasty experienced more spontaneous sexual desire compared with those who planned this surgery but had not yet undergone it (P = 0.03). In retrospect, the majority of trans men (71.0%) reported an increase in sexual desire after SRT. Thirty percent of trans men never or rarely felt sexual desire; 39.7% from time to time, and 30.6% often or always. Five percent of trans men met the criteria for HSDD. Trans men who were less satisfied with the phalloplasty had a higher prevalence of HSDD (P = 0.02). Trans persons who were more satisfied with the hormonal therapy had a lower prevalence of HSDD (P = 0.02). HSDD was more prevalent in trans women compared with trans men. The majority of trans women reported a decrease in sexual desire after SRT, whereas the opposite was observed in trans men. Our results show a significant sexual impact of surgical interventions and both hormonal and surgical treatment satisfaction on the sexual desire in trans persons. © 2013 International Society for Sexual

  12. IEEE Xplore® Digital Library - Evolving to Meet YOUR Changing Needs

    OpenAIRE

    2014-01-01

    Представлена презентация доклада "Использование платформы IEEE Digital Library: уникальные научные публикации в области электроники, радиосвязи, вычислительной техники, информационных технологий, энергетики, машиностроения, физики, химии, геологии, нанотехнологий" Эстер Лукаш, специалиста по обучению IEEE (Германия), на семинаре «Использование платформы IEEE Digital Library», прошедшем 02 октября 2014 года в УрФУ, на английском языке....

  13. Uso do sulfato de magnésio venoso para tratamento da asma aguda grave da criança no pronto-socorro

    Directory of Open Access Journals (Sweden)

    Tânia Mara Baraky Bittar

    2012-03-01

    Full Text Available A asma aguda grave é uma emergência médica que deve ser diagnosticada e tratada rapidamente. O tratamento inicial inclui broncodilatadores e corticosteróides sistêmicos. Em casos graves, com fraca resposta ao tratamento padrão, o sulfato de magnésio venoso surge como opção terapêutica. O objetivo deste artigo foi revisar a literatura sobre o uso do sulfato de magnésio venoso na asma aguda em crianças no pronto-socorro no que se refere a eficácia, indicação, dosagem, efeitos adversos e contraindicações. Realizada revisão narrativa por meio das Bases de dados Medline, Lilacs e Cochrane Database of Systmatic Reviews, entre 2000 e 2010. Utilizados os descritores: asthma, children, emergency, magnesium sulfate. Incluídos oito ensaios clínicos controlados, três meta-análises, um estudo retrospectivo, oito artigos de revisão e um estudo transversal. A eficácia do magnésio venoso em crianças foi observada por vários autores, com raros efeitos adversos. Seu uso foi indicado para os pacientes com asma aguda moderada e grave que não responderam ao tratamento inicial com broncodilatador e corticosteróide. As contraindicações em pediatria são poucas. Entre elas estão insuficiência renal e bloqueio atrioventricular. Existem poucos relatos da interação do magnésio com drogas de uso pediátrico. Apesar da segurança, na prática, o magnésio venoso é pouco usado na asma aguda em pediatria. Na maioria das vezes, é indicado tardiamente para impedir falência respiratória e internação na unidade de cuidados intensivos. Os estudos demonstram que o magnésio venoso é uma droga eficaz e segura na criança com asma aguda grave, porém o seu uso no pronto-socorro ainda é limitado.

  14. Medidas morfofuncionais do coração obtidas por ressonância magnética em brasileiros

    Directory of Open Access Journals (Sweden)

    Robson Macedo

    2013-07-01

    Full Text Available FUNDAMENTO: Medidas ainda hoje utilizadas como referência na ressonância magnética cardíaca foram obtidas principalmente de estudos realizados em populações norte-americanas e europeias. OBJETIVO: Obter medidas do diâmetro diastólico, diâmetro sistólico, volume diastólico final, volume sistólico final, fração de ejeção e massa miocárdica dos ventrículos esquerdo e direito em brasileiros. MÉTODOS: Foram submetidos à ressonância magnética cardíaca, utilizando técnica de precessão livre em estado de equilíbrio, 54 homens e 53 mulheres, com idade média de 43,4 ± 13,1 anos, assintomáticos, sem cardiopatias. RESULTADOS: As médias e os desvios padrão dos parâmetros do ventrículo esquerdo foram: diâmetro diastólico = 4,8 ± 0,5 cm; diâmetro sistólico = 3,0 ± 0,6 cm; volume diastólico final = 128,4 ± 29,6 mL; volume sistólico final = 45,2 ± 16,6 mL; fração de ejeção = 65,5 ± 6,3%; massa = 95,2 ± 30,8 g. Para o ventrículo direito, foram: diâmetro diastólico = 3,9 ± 1,3 cm; diâmetro sistólico = 2,5 ± 0,5 cm; volume diastólico final = 126,5 ± 30,7 mL; volume sistólico final = 53,6 ± 18,4 mL; fração de ejeção = 58,3 ± 8,0% e massa = 26,1 ± 6,1 g. As massas e os volumes foram significativamente maiores nos homens, exceto para o volume sistólico final do ventrículo esquerdo. A fração de ejeção do ventrículo direito foi significativamente maior nas mulheres. Houve correlação significativa e inversa do volume sistólico do volume direito com o aumento da idade. CONCLUSÃO: Este estudo descreveu, pela primeira vez, medidas cardíacas obtidas pela ressonância magnética cardíaca em brasileiros assintomáticos, sem cardiopatias, mostrando diferenças de acordo com o gênero e a idade.

  15. Fault-Tolerant Topology and Routing Synthesis for IEEE Time-Sensitive Networking

    DEFF Research Database (Denmark)

    Gavrilut, Voica Maria; Zarrin, Bahram; Pop, Paul

    2017-01-01

    of the applications are satisffied. We propose three approaches to solve this optimization problem: (1) a heuristic solution, (2) a Greedy Randomized Adaptive Search Procedure (GRASP) metaheuristic, and (3) a Constraint Programmingbased model. The approaches are evaluated on several test cases, including a test case......Time-Sensitive Networking (TSN) is a set of IEEE standards that extend Ethernet for safety-critical and real-time applications. TSN is envisioned to be widely used in several applications areas, from industrial automation to in-vehicle networking. A TSN network is composed of end systems...... interconnected by physical links and bridges (switches). The data in TSN is exchanged via streams. We address safety-critical real-time systems, and we consider that the streams use the Urgency-Based Scheduler (UBS) traffic-type, suitable for hard real-time traffic. We are interested in determining a fault...

  16. Synchronous ethernet and IEEE 1588 in telecoms next generation synchronization networks

    CERN Document Server

    2013-01-01

    This book addresses the multiple technical aspects of the distribution of synchronization in new generation telecommunication networks, focusing in particular on synchronous Ethernet and IEEE1588 technologies. Many packet network engineers struggle with understanding the challenges that precise synchronization distribution can impose on networks. The usual “why”, “when” and particularly “how” can cause problems for many engineers. In parallel to this, some other markets have identical synchronization requirements, but with their own design requirements, generating further questions. This book attempts to respond to the different questions by providing background technical information. Invaluable information on state of-the-art packet network synchronization and timing architectures is provided, as well as an unbiased view on the synchronization technologies that have been internationally standardized over recent years, with the aim of providing the average reader (who is not skilled in the art) wi...

  17. 12th ACIS/IEEE International Conference on Computer Science and Information Science

    CERN Document Server

    2013-01-01

    This edited book presents scientific results of the 12th IEEE/ACIS International Conference on Computer and Information Science (ICIS 2013) which was held on June 16-20, 2013 in Toki Messe, Niigata, Japan. The aim of this conference was to bring together scientists, engineers, computer users, and students to share their experiences and exchange new ideas, research results about all aspects (theory, applications and tools) of computer and information science, and to discuss the practical challenges encountered along the way and the solutions adopted to solve them The conference organizers selected the best 20 papers from those papers accepted for presentation at the conference. The papers were chosen based on review scores submitted by members of the program committee, and underwent further rigorous rounds of review.    

  18. Efficient Beacon Collision Resolution Procedure for IEEE 802.15.4 /Zigbee Wireless Personal Area Networks

    Directory of Open Access Journals (Sweden)

    Bassam A. Zafar

    2017-04-01

    Full Text Available While IEEE 802.15.4/Zigbee is a promising technology for Wireless Personal Area Networks, several transmission problems are not yet resolved. In particular, the problem of beacon transmission interferences is causing the device connection loss to the network. In order to resolve this problem, we present a new distributed and reactive procedure for beacon collision resolution. It is an extension of the alignment procedure to reorganize randomly the beacon transmission time when a collision has occurred. The detail of the proposed procedure will be fully described and analyzed. The performance of our approach is performed by simulations. The results show that our approach reduces the collision probability and the device disconnections consequently.

  19. The IEEE guide to writing in the engineering and technical fields

    CERN Document Server

    Kmiec, David

    2017-01-01

    This book introduces students and practicing engineers to all the components of writing in the workplace. It teaches readers how considerations of audience and purpose govern the structure of their documents within particular work settings. The IEEE Guide to Writing in the Engineering and Technical Fields is broken up into two sections: "Writing in Engineering Organizations" and "What Can You Do With Writing?" The first section helps readers approach their writing in a logical and persuasive way as well as analyze their purpose for writing. The second section demonstrates how to distinguish rhetorical situations and the generic forms to inform, train, persuade, and collaborate. The emergence of the global workplace has brought with it an increasingly important role for effective technical communication. Engineers more often need to work in cross-functional teams with people in different disciplines, in different countries, and in different parts of the world. Engineers must know how to communicate in a rapid...

  20. Development of a low mobility IEEE 802.15.4 compliant VANET system for urban environments.

    Science.gov (United States)

    Nazabal, Juan Antonio; Falcone, Francisco; Fernández-Valdivielso, Carlos; Matías, Ignacio Raúl

    2013-05-29

    The use of Vehicular Ad-Hoc Networks (VANETs) is growing nowadays and it includes both roadside-to-vehicle communication (RVC) and inter-vehicle communication (IVC). The purpose of VANETs is to exchange useful information between vehicles and the roadside infrastructures for making an intelligent use of them. There are several possible applications for this technology like: emergency warning system for vehicles, cooperative adaptive cruise control or collision avoidance, among others. The objective of this work is to develop a VANET prototype system for urban environments using IEEE 802.15.4 compliant devices. Simulation-based values of the estimated signal strength and radio link quality values are obtained and compared with measurements in outdoor conditions to validate an implemented VANET system. The results confirm the possibility of implementing low cost vehicular communication networks operating at moderate vehicular speeds.

  1. 2011 IEEE Visualization Contest winner: Visualizing unsteady vortical behavior of a centrifugal pump.

    Science.gov (United States)

    Otto, Mathias; Kuhn, Alexander; Engelke, Wito; Theisel, Holger

    2012-01-01

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump's effectiveness. The winning entry split analysis of the pump into three parts based on the pump's functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump.

  2. Vispubdata.org: A Metadata Collection About IEEE Visualization (VIS) Publications.

    Science.gov (United States)

    Isenberg, Petra; Heimerl, Florian; Koch, Steffen; Isenberg, Tobias; Xu, Panpan; Stolper, Charles D; Sedlmair, Michael; Chen, Jian; Moller, Torsten; Stasko, John

    2017-09-01

    We have created and made available to all a dataset with information about every paper that has appeared at the IEEE Visualization (VIS) set of conferences: InfoVis, SciVis, VAST, and Vis. The information about each paper includes its title, abstract, authors, and citations to other papers in the conference series, among many other attributes. This article describes the motivation for creating the dataset, as well as our process of coalescing and cleaning the data, and a set of three visualizations we created to facilitate exploration of the data. This data is meant to be useful to the broad data visualization community to help understand the evolution of the field and as an example document collection for text data visualization research.

  3. Beamforming transmission in IEEE 802.11ac under time-varying channels.

    Science.gov (United States)

    Yu, Heejung; Kim, Taejoon

    2014-01-01

    The IEEE 802.11ac wireless local area network (WLAN) standard has adopted beamforming (BF) schemes to improve spectral efficiency and throughput with multiple antennas. To design the transmit beam, a channel sounding process to feedback channel state information (CSI) is required. Due to sounding overhead, throughput increases with the amount of transmit data under static channels. Under practical channel conditions with mobility, however, the mismatch between the transmit beam and the channel at transmission time causes performance loss when transmission duration after channel sounding is too long. When the fading rate, payload size, and operating signal-to-noise ratio are given, the optimal transmission duration (i.e., packet length) can be determined to maximize throughput. The relationship between packet length and throughput is also investigated for single-user and multiuser BF modes.

  4. Fir Filters Compliant with the IEEE Standard for M Class PMU

    Directory of Open Access Journals (Sweden)

    Duda Krzysztof

    2016-12-01

    Full Text Available In this paper it is shown that M class PMU (Phasor Measurement Unit reference model for phasor estimation recommended by the IEEE Standard C37.118.1 with the Amendment 1 is not compliant with the Standard. The reference filter preserves only the limits for TVE (total vector error, and exceeds FE (frequency error and RFE (rate of frequency error limits. As a remedy we propose new filters for phasor estimation for M class PMU that are fully compliant with the Standard requirements. The proposed filters are designed: 1 by the window method; 2 as flat-top windows; or as 3 optimal min-max filters. The results for all Standard compliance tests are presented, confirming good performance of the proposed filters. The proposed filters are fixed at the nominal frequency, i.e. frequency tracking and adaptive filter tuning are not required, therefore they are well suited for application in lowcost popular PMUs.

  5. IEEE [Institute of Electrical and Electronics Engineers] standards and nuclear software quality engineering

    International Nuclear Information System (INIS)

    Daughtrey, T.

    1988-01-01

    Significant new nuclear-specific software standards have recently been adopted under the sponsorship of the American Nuclear Society and the American Society of Mechanical Engineers. The interest of the US Nuclear Regulatory Commission has also been expressed through their issuance of NUREG/CR-4640. These efforts all indicate a growing awareness of the need for thorough, referenceable expressions of the way to build in and evaluate quality in nuclear software. A broader professional perspective can be seen in the growing number of software engineering standards sponsored by the Institute of Electrical and Electronics Engineers (IEEE) Computer Society. This family of standards represents a systematic effort to capture professional consensus on quality practices throughout the software development life cycle. The only omission-the implementation phase-is treated by accepted American National Standards Institute or de facto standards for programming languages

  6. 3th IEEE/ACIS International Conference on Computer and Information Science

    CERN Document Server

    2015-01-01

    This edited book presents scientific results of the 13th IEEE/ACIS International Conference on Computer and Information Science (ICIS 2014) which was held on June 4-6, 2014 in Taiyuan, China. The aim of this conference was to bring together researchers and scientists, businessmen and entrepreneurs, teachers, engineers, computer users, and students to discuss the numerous fields of computer science and to share their experiences and exchange new ideas and information in a meaningful way. Research results about all aspects (theory, applications and tools) of computer and information science, and to discuss the practical challenges encountered along the way and the solutions adopted to solve them. The conference organizers selected the best papers from those papers accepted for presentation at the conference.  The papers were chosen based on review scores submitted by members of the program committee, and underwent further rigorous rounds of review. This publication captures 14 of the conference’s most promis...

  7. Delay efficient cooperation in public safety vehicular networks using LTE and IEEE 802.11p

    KAUST Repository

    Atat, Rachad

    2012-01-01

    Cooperative schemes for critical content distribution over vehicular networks are presented and analyzed. The first scheme is based on unicasting from the base station, whereas the second is based on threshold based multicasting. Long Term Evolution (LTE) is used for long range communications with the base station (BS) and 802.11p is considered for inter-vehicle collaboration on the short range. A high mobility environment with correlated shadowing is adopted. Both schemes are shown to outperform non-cooperative unicasting and multicasting, respectively, when the appropriate 802.11p power class is used. The first scheme achieves the best performance among the compared methods, and a practical approximation of that scheme is shown to be close to optimal performance. © 2012 IEEE.

  8. Dynamic Voltage Stability Studies using a Modified IEEE 30-Bus System

    Directory of Open Access Journals (Sweden)

    Oluwafemi Emmanuel Oni

    2016-09-01

    Full Text Available Power System stability is an essential study in the planning and operation of an efficient, economic, reliable and secure electric power system because it encompasses all the facet of power systems operations, from planning, to conceptual design stages of the project as well as during the systems operating life span. This paper presents different scenario of power system stability studies on a modified IEEE 30-bus system which is subjected to different faults conditions. A scenario whereby the longest high voltage alternating current (HVAC line is replaced with a high voltage direct current (HVDC line was implemented. The results obtained show that the HVDC line enhances system stability more compared to the contemporary HVAC line. Dynamic analysis using RMS simulation tool was used on DigSILENT PowerFactory.

  9. Reliable Multicast MAC Protocol for IEEE 802.11 Wireless LANs with Extended Service Range

    Science.gov (United States)

    Choi, Woo-Yong

    2011-11-01

    In this paper, we propose the efficient reliable multicast MAC protocol by which the AP (Access Point) can transmit reliably its multicast data frames to the recipients in the AP's one-hop or two-hop transmission range. The AP uses the STAs (Stations) that are directly associated with itself as the relays for the data delivery to the remote recipients that cannot be reached directly from itself. Based on the connectivity information among the recipients, the reliable multicast MAC protocol optimizes the number of the RAK (Request for ACK) frame transmissions in a reasonable computational time. Numerical examples show that our proposed MAC protocol significantly enhances the MAC performance compared with the BMMM (Batch Mode Multicast MAC) protocol that is extended to support the recipients that are in the AP's one-hop or two-hop transmission range in IEEE 802.11 wireless LANs.

  10. Experimental video signals distribution MMF network based on IEEE 802.11 standard

    Science.gov (United States)

    Kowalczyk, Marcin; Maksymiuk, Lukasz; Siuzdak, Jerzy

    2014-11-01

    The article was focused on presentation the achievements in a scope of experimental research on transmission of digital video streams in the frame of specially realized for this purpose ROF (Radio over Fiber) network. Its construction was based on the merge of wireless IEEE 802.11 network, popularly referred as Wi-Fi, with a passive optical network PON based on multimode fibers MMF. The proposed approach can constitute interesting proposal in area of solutions in the scope of the systems monitoring extensive, within which is required covering of a large area with ensuring of a relatively high degree of immunity on the interferences transmitted signals from video IP cameras to the monitoring center and a high configuration flexibility (easily change the deployment of cameras) of such network.

  11. Mobile Device Passive Localization Based on IEEE 802.11 Probe Request Frames

    Directory of Open Access Journals (Sweden)

    Lin Sun

    2017-01-01

    Full Text Available This paper presents a novel passive mobile device localization mode based on IEEE 802.11 Probe Request frames. In this approach, the listener can discover mobile devices by receiving the Probe Request frames and localize them on his walking path. The unique location of the mobile device is estimated on a geometric diagram and right-angled walking path. In model equations, site-related parameter, that is, path loss exponent, is eliminated to make the approach site-independent. To implement unique localization, the right-angled walking path is designed and the optimal location is estimated from the optional points. The performance of our method has been evaluated inside the room, outside the room, and in outdoor scenarios. Three kinds of walking paths, for example, horizontal, vertical, and slanted, are also tested.

  12. IEEE 1394/firewire a low cost, high speed, digital serial bus

    Energy Technology Data Exchange (ETDEWEB)

    Gaunt, R.

    1997-05-01

    Does the world need yet another 1/0 bus standard? If you need fast and cheap serial video communication, then the answer is yes. As technology advances, so too must data transport mechanisms advance. You can`t expect RS-232 to support real-time digital video, and if you can`t afford expensive professional serial video interfaces, (such as Sony`s Serial Digital Interface), Firewire may be a good solution. IEEE 1394, or commonly known as Firewire, is a general purpose serial bus that meets many of the 1/0 needs of today`s video and multimedia developers. For those of you who only read the first paragraph, here`s Firewire in a nutshell: It provides a guaranteed transfer rate of 10OMbps or 20OMbps of digital data (such as video direct from camera to computer), over an inexpensive, non-proprietary serial bus. Here is a list of its features.

  13. Trans fats in New Zealand: time for labelling regulations?

    Science.gov (United States)

    Gladding, Patrick; Benatar, Jocelyne R

    2007-11-09

    Trans fats (trans fatty acids) are commonly used for deep frying in restaurants and in the fast food, snack food, fried food, and baked goods industries, often to extend the shelf life of foods. However they are widely considered to be harmful to health. Trans fats were banned in New York City restaurants from 1 July 2007, and there is growing vocal opposition to trans fats in the European Union. Denmark became the first country, in March 2003, to introduce laws regulating the content of trans fats in food (maximum of 2% of edible fats and oils). What are trans fats, what harm do they cause, and should New Zealand also consider imposing mandatory regulations on their use in food? This article explores the issues.

  14. Nuclear reactions: Science and trans-science

    International Nuclear Information System (INIS)

    Weinberg, A.M.

    1992-01-01

    This book is a collection of essays written by Weinberg over the span of his scientific and administrative career. A sound theorist, he was introduced to nuclear physics as part of the Manhattan project, and assumed administrative responsibilities during that project. His career has allowed him to make valuable contributions in a broad range of fields. These essays touch on topics of interest to him, concern to the country, and of profound import for society as it exists today. They are grouped into five sections: science and trans-science; scientific administration; strategic defense and arms control; time, energy and resources; nuclear energy

  15. TRAN-STAT: statistics for environmental studies

    International Nuclear Information System (INIS)

    Gilbert, R.O.

    1984-09-01

    This issue of TRAN-STAT discusses statistical methods for assessing the uncertainty in predictions of pollutant transport models, particularly for radionuclides. Emphasis is placed on radionuclide transport models but the statistical assessment techniques also apply in general to other types of pollutants. The report begins with an outline of why an assessment of prediction uncertainties is important. This is followed by an introduction to several methods currently used in these assessments. This in turn is followed by more detailed discussion of the methods, including examples. 43 references, 2 figures

  16. A Study of IEEE 802.15.4 Security Framework for Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Kyung Sup Kwak

    2011-01-01

    Full Text Available A Wireless Body Area Network (WBAN is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE applications. Since WBAN nodes are used to collect sensitive (life-critical information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS attacks in WBAN at Physical, Medium Access Control (MAC, Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP and Contention Free Period (CFP parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS in WBAN (since most of the data is carried in CFP period. As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN.

  17. A study of IEEE 802.15.4 security framework for wireless body area networks.

    Science.gov (United States)

    Saleem, Shahnaz; Ullah, Sana; Kwak, Kyung Sup

    2011-01-01

    A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS) in WBAN (since most of the data is carried in CFP period). As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN.

  18. Meningiomas parasselares: aspectos na ressonância magnética Parasellar meningiomas: magnetic resonance imaging findings

    Directory of Open Access Journals (Sweden)

    Alair Augusto S.M.D. dos Santos

    2001-02-01

    Full Text Available Foram revistos 22 casos de meningiomas parasselares avaliados por ressonância magnética em clínicas privadas nas cidades de Niterói e Rio de Janeiro, RJ. O objetivo deste trabalho é demonstrar os aspectos de imagem encontrados neste tumor. Os equipamentos utilizados tinham 0,5 e 1,0 Tesla, respectivamente, com aquisição de seqüências multiplanares ponderadas em T1 (antes e após a administração de gadolínio e em T2. Os sintomas principais foram cefaléia e alterações visuais, tendo apenas um caso cursado com hiperprolactinemia. O aspecto mais freqüente foi o de massa parasselar hipointensa em T1 e hiperintensa em T2, impregnando-se intensamente pelo gadolínio. A ressonância magnética é útil não apenas na demonstração da lesão mas, sobretudo, na avaliação do comprometimento das estruturas vizinhas, especialmente do seio cavernoso, o que explica as alterações visuais encontradas.We reviewed 22 cases of patients with parasellar meningiomas evaluated with magnetic resonance imaging (MRI in private clinics of the cities of Niterói and Rio de Janeiro, RJ, Brazil. Our aim was to characterize the imaging findings in this type of tumor. MRI scanners with 0.5 and 1.0 Tesla magnets were used for the acquisition of multiplanar T1-weighted (pre- and post-gadolinium administration and T2-weighted images. The main symptoms observed were headache and visual disturbances. Hyperprolactinemia was observed in only one patient. The most frequent imaging finding was a parasellar mass which appeared hypointense on T1-weighted and hyperintense on T2-weighted images, and enhanced intensively after gadolinium administration. MRI is useful to demonstrate the lesion and to assess the damage to adjacent structures, particularly when the patient presents visual disturbances due to involvement of the cavernous sinuses.

  19. Análisis, cálculo y técnicas de mitigación de campos magnéticos creados por líneas eléctricas de alta tensión

    OpenAIRE

    Cruz Romero, Pedro Luis

    2000-01-01

    La tesis consiste en el desarrollo de un modelo de cálculo de campos magnéticos creados por líneas eléctricas aéreas, que permita, por un lado analizar las configuraciones existentes en relación con el campo magnético generado, y por otro estudiar diferentes técnicas de mitigación del campo magnético. En particular, se analizan la división de fases y la colocación de lazos pasivos y activos. Para el priemr método se obtienen las configuraciones que minimizan el campo magnético a diferentes di...

  20. Structural modification of trans-cinnamic acid using Colletotrichum acutatum

    OpenAIRE

    Velasco B., Rodrigo; Gil G., Jesús H.; García P., Carlos M.; Durango R., Diego L.

    2012-01-01

    The biotransformation of trans-cinnamic acid by whole cells of the Colombian native phytopathogenic fungus Colletotrichum acutatum was studied. Initially, fungitoxicity of this compound against C. acutatum was evaluated; trans-cinnamic acid exhibited a moderate to weak toxicity against the microorganism and apparently a detoxification mechanism was present. Then, in order to study such mechanism and explore the capacity of this fungus to biotransform trans-cinnamic acid into value-added produ...

  1. Trans-nationalisation Processes in the Ukrainian Economy

    OpenAIRE

    Bolharova Natalya K.; Panevnyk Tetyana M.

    2013-01-01

    The article considers main processes of trans-nationalisation of Ukrainian economy, identifies specific features of trans-national production and explains some theoretical aspects of these issues. It provides main stages of theoretical comprehension of activity of trans-national corporations (TNC), specific features of the theory of competitive advantages of TNC and specifies the basic ones of them. The article conducts analysis of flows of direct foreign investments into the Ukrainian econom...

  2. Trans*Forming College Masculinities: Carving out Trans*Masculine Pathways through the Threshold of Dominance

    Science.gov (United States)

    Jourian, T. J.

    2017-01-01

    Men and masculinities studies are gaining prominence in higher education literature, illuminating how cisgender college men understand and grapple with masculinity. Additionally, the increased visibility of trans* students has fueled the expanding scholarship and attention to their experiences, often however centering on white gender-conforming…

  3. Trans advanced surface laser ablation (TransPRK) outcomes using SmartPulseTechnology.

    Science.gov (United States)

    Aslanides, Ioannis M; Kymionis, George D

    2017-02-01

    To evaluate early visual rehabilitation, post-operative pain, epithelial healing and haze after transepithelial photorefractive keratectomy (TransPRK) using the SmartPulseTechnology (SPT) of Schwind Amaris (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany). This was a retrospective comparative evaluation of a cohort of myopic patients undergoing TransPRK with SPT (group 1), with one matched control group that underwent conventional TransPRK (group 2). All cases had a 6-month post-operative follow-up including visual acuity and slit-lamp examination. Subjective evaluation of pain was recorded post-operatively. 49 eyes of 25 patients in group 1 and 40 eyes of 20 patients in group 2 were enrolled. The patients' visual rehabilitation was significantly faster in group 1, one day and one week post-operatively (P0.05). TransPRK using SPT provides promising results in the early post-operative period. Visual rehabilitation, re-epithelialization and pain were faster in the early post-operative period in group 1 in comparison with group 2. Haze formation was not significantly different between the two groups; however, it was consistently less in group 1. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  4. Trans-nationalizing the African Public Sphere: What Role for Trans ...

    African Journals Online (AJOL)

    seriane.camara

    2011-03-09

    Mar 9, 2011 ... At a time when the notion of 'trans-national public spheres' is gaining .... ple refer specifically to the language and its speakers in Senegal and Mauri- .... of the Pulaar language and the improvement of the social and economic.

  5. A trans European Union difference in the decline in trans fatty acids in popular foods

    DEFF Research Database (Denmark)

    Stender, Steen; Astrup, Arne; Dyerberg, Jørn

    2012-01-01

    To minimise the intake of industrial trans fatty acids (I-TFA) some countries have introduced labelling, while others have introduced legislative limits on the content of I-TFA in food. However, most countries still rely on food producers to voluntarily reduce the I-TFA content in food. The objec...

  6. Spectroscopic and density functional theory studies of trans-3-(trans-4-imidazolyl)acrylic acid.

    Science.gov (United States)

    Arjunan, V; Remya, P; Sathish, U; Rani, T; Mohan, S

    2014-08-14

    The structural parameters, thermodynamic properties and vibrational frequencies of the optimised geometry of trans-3-(trans-4-imidazolyl)acrylic acid have been determined from B3LYP methods with 6-311++G(**) and cc-pVTZ basis sets. The effects of substituents (acrylyl group) on the imidazole vibrational frequencies are analysed. The vibrational frequencies of the fundamental modes of trans-3-(trans-4-imidazolyl)acrylic acid have been precisely assigned and analysed and the theoretical results are compared with the experimental vibrations. (1)H and (13)C NMR isotropic chemical shifts are calculated and the assignments made are compared with the experimental values. The energies of important MO's of the compound are also determined from DFT method. The total electron density and electrostatic potential of the compound are determined by natural bond orbital analysis. Various reactivity and selectivity descriptors such as chemical hardness, chemical potential, softness, electrophilicity, nucleophilicity and the appropriate local quantities employing natural population analysis (NPA) are calculated. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Propiedades magnéticas y micromorfología de suelos en el sitio arqueológico Marazzi 2, Isla Grande de Tierra del Fuego, Chile

    OpenAIRE

    Ozán, Ivana Laura; Orgeira, Maria Julia

    2017-01-01

    El objetivo del presente trabajo es investigar el origen de la señal magnética (natural y/o antrópica) y su vinculación con la micromorfología de suelos, en dos perfiles del sitio arqueológico Marazzi 2, perteneciente al Holoceno tardío y ubicado en el noroeste de la Isla Grande de Tierra del Fuego (Chile). Los resultados muestran que el perfil P1 presenta un pico de la señal magnética (presencia de magnetita y/o titanomagnetita) entre los 30 - 70 cm, que coincide con un horizonte Ab y ABb en...

  8. Modelos globales del campo magnético terrestre para los últimos 3000 años: discrepancias según las bases de datos usadas

    OpenAIRE

    Campuzano, S. A.; Gómez-Paccard, Miriam; Pavón-Carrasco, Fco. Javier; Osete, María Luisa

    2016-01-01

    La modelización global del campo magnético terrestre no es sólo fundamental para comprender cómo funciona y varía en el tiempo, sino también para constreñir los modelos de geodinamo y corregir las tasas de producción de isótopos cosmogénicos. Obtener modelos suficientemente realistas depende en gran medida de las bases de datos empleadas. Los datos arqueomagnéticos y volcánicos proporcionan un registro casi instantáneo del campo, debido al proceso de adquisición de la remanencia magnética (te...

  9. Quantificação de fluxo do líquido cefalorraquidiano (LCR) por ressonância magnética

    OpenAIRE

    Jesuíta, Patrícia Filipa

    2012-01-01

    Mestrado em Radiações Aplicadas às Tecnologias da Saúde. Especialização: Ressonância Magnética. Para que a identificação da hidrocefalia normotensiva ou comunicante crónica do adulto, possa ser identificada através de exames de quantificação de fluxo do LCR no aqueduto de Sylvius através de imagem por ressonância magnética de contraste de fase é necessário conhecer quais os valores normativos para indivíduos adultos e saudáveis. Esta Investigação tem como objectivo a determinação desses va...

  10. Cálculo e análise de efeitos de campo magnético nos estados eletrônicos de impurezas rasas em materiais semicondutores

    OpenAIRE

    Souza, Gustavo Vanin Bernardino de [UNESP

    2009-01-01

    São calculados os níveis de energia para o átomo de hidrogênio sob campo magnético uniforme, utilizando o método das diferenças finitas. Estes resultados, quando multiplicados pelo Rydberg efetivo (que depende da massa efetiva e da permitividade elétrica do meio) correspondem à solução do problema de um elétron ligado a uma impureza doadora rasa em um semicondutor sob campo magnético (caso isotrópico, parabólico, não degenerado). Os valores encontrados, para campo nulo, são comparados com a s...

  11. [CONTENT OF TRANS FATTY ACIDS IN FOOD PRODUCTS IN SPAIN].

    Science.gov (United States)

    Robledo de Dios, Teresa; Dal Re Saavedra, M Ángeles; Villar Villalba, Carmen; Pérez-Farinós, Napoleón

    2015-09-01

    trans fatty acids are associated to several health disorders, as ischemic heart disease or diabetes mellitus. to assess the content of trans fatty acids in products in Spain, and the percentage of trans fatty acids respecting total fatty acids. 443 food products were acquired in Spain, and they were classified into groups. The content in fatty acids was analyzed using gas chromatography. Estimates of central tendency and variability of the content of trans fatty acids in each food group were computed (in g of trans fatty acids/100 g of product). The percentage of trans fatty acids respecting total fatty acids was calculated in each group. 443 products were grouped into 42 groups. Median of trans fatty acids was less than 0.55 g / 100 g of product in all groups except one. 83 % of groups had less than 2 % of trans fatty acids, and 71 % of groups had less than 1 %. the content of trans fatty acids in Spain is low, and it currently doesn't play a public health problem. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  12. Is there such a thing as Tech Trans?

    DEFF Research Database (Denmark)

    Helms, Niels Henrik

    2009-01-01

    This short paper is an attempt to start a discussion on some basic issues within the concept of Tech Trans especially the relationship between flow and structure within the concept. The background to this paper is first of all an academic interest in the relationship between flow and structure...... explores the concept of Tech Trans, show rooms and innovation systems, and it suggests that the notion of Tech Trans should be defined in the fix point of vertical and horizontal innovation. Finally this paper suggests a mathematical formula for evaluating Tech Trans....

  13. Toxicidad por dosis repetidas de la solución CM-95 tratada magnéticamente en ratas Sprague Dawley

    Directory of Open Access Journals (Sweden)

    Clara E. Martínez

    2008-08-01

    Full Text Available En este trabajo se realizó la evaluación toxicológica a dosis repetidas por el método de test límite del candidato a inmunopotenciador, la solución CM-95 tratada magnéticamente, acorde con las regulaciones de la Organización para la Colaboración Económica y el Desarrollo, incluida en la Guía 407. El objetivo fue establecer las posibles lesiones orgánicas y funcionales ocasionadas por la solución CM-95, tratada magnéticamente con la máxima inducción magnética permisible (0,16 T, para la obtención del candidato a inmunopotenciador. Se emplearon tres grupos: Experimental, Control y Satélite. Como Biomodelo experimental se utilizaron ratas Sprague Dawley machos y hembras con pesos de 150 a 200 g. Durante el estudio no se registraron signos clínicos de toxicidad ni muertes en ninguno de los animales de los grupos tratados, ni en los controles. No hubo afectación del peso corporal durante el ensayo. Aunque hubo variaciones en los valores de algunos parámetros hematológicos y bioquímicos, estos no tuvieron significación biológica. No se encontraron lesiones macroscópicas, ni microscópicas; solo se observaron efectos proliferativos en el tejido linfoide de timo y bazo, relacionados con la respuesta del sistema inmune. La solución CM-95 tratada magnéticamente, no mostró toxicidad en el modelo animal y nivel de dosis utilizado, y bajo las condiciones experimentales ensayadas.

  14. Hipnose para controle de claustrofobia em exames de ressonância magnética Hypnosis for management of claustrophobia in magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Luiz Guilherme Carneiro Velloso

    2010-02-01

    Full Text Available OBJETIVO: Testar a eficácia da hipnose para o controle de claustrofobia em pacientes submetidos a exames de ressonância magnética. MATERIAIS E MÉTODOS: Vinte pacientes claustrofóbicos, com indicação de sedação para ressonância magnética, foram submetidos a hipnose pela técnica de Braid. Os pacientes suscetíveis à hipnose foram encaminhados para realização do exame em estado de transe hipnótico, sem uso de medicamentos para sedação. RESULTADOS: Da amostra estudada, 18 casos (90% foram suscetíveis à técnica. Dos 16 pacientes sensíveis à hipnose que compareceram para a ressonância magnética, 15 (93,8% realizaram o exame em transe hipnótico, sem ocorrência de crise de claustrofobia e sem necessitar de medicamentos para sedação. CONCLUSÃO: Hipnose é uma alternativa para a sedação medicamentosa em pacientes claustrofóbicos que necessitam realizar ressonância magnética.OBJECTIVE: To evaluate the efficacy of hypnosis for management of claustrophobia in patients submitted to magnetic resonance imaging. MATERIALS AND METHODS: Twenty claustrophobic patients referred for magnetic resonance imaging under sedation were submitted to hypnosis using the Braid technique. The patients susceptible to hypnosis were submitted to magnetic resonance imaging under hypnotic trance without using sedative drugs. RESULTS: Out of the sample, 18 (90% patients were susceptible to the technique. Of the 16 hypnotizable subjects who were submitted to magnetic resonance imaging, 15 (93.8% could complete the examination under hypnotic trance, with no sign of claustrophobia and without need of sedative drugs. CONCLUSION: Hypnosis is an alternative to anesthetic sedation for claustrophobic patients who must undergo magnetic resonance imaging.

  15. Direct synthesis of pure single-crystalline Magnéli phase Ti8O15 nanowires as conductive carbon-free materials for electrocatalysis

    Science.gov (United States)

    He, Chunyong; Chang, Shiyong; Huang, Xiangdong; Wang, Qingquan; Mei, Ao; Shen, Pei Kang

    2015-02-01

    The Magnéli phase Ti8O15 nanowires (NWs) have been grown directly on a Ti substrate by a facile one-step evaporation-deposition synthesis method under a hydrogen atmosphere. The Ti8O15 NWs exhibit an outstanding electrical conductivity at room temperature. The electrical conductivity of a single Ti8O15 nanowire is 20.6 S cm-1 at 300 K. Theoretical calculations manifest that the existence of a large number of oxygen vacancies changes the band structure, resulting in the reduction of the electronic resistance. The Magnéli phase Ti8O15 nanowires have been used as conductive carbon-free supports to load Pt nanoparticles for direct methanol oxidation reaction (MOR). The Pt/Ti8O15 NWs show an enhanced activity and extremely high durability compared with commercial Pt/C catalysts.The Magnéli phase Ti8O15 nanowires (NWs) have been grown directly on a Ti substrate by a facile one-step evaporation-deposition synthesis method under a hydrogen atmosphere. The Ti8O15 NWs exhibit an outstanding electrical conductivity at room temperature. The electrical conductivity of a single Ti8O15 nanowire is 20.6 S cm-1 at 300 K. Theoretical calculations manifest that the existence of a large number of oxygen vacancies changes the band structure, resulting in the reduction of the electronic resistance. The Magnéli phase Ti8O15 nanowires have been used as conductive carbon-free supports to load Pt nanoparticles for direct methanol oxidation reaction (MOR). The Pt/Ti8O15 NWs show an enhanced activity and extremely high durability compared with commercial Pt/C catalysts. Electronic supplementary information (ESI) available: Additional data for the characterization and experimental details see DOI: 10.1039/c4nr05806b

  16. Tamaño auricular y realce miocárdico en la miocardiopatía hipertrófica mediante resonancia magnética

    OpenAIRE

    Méndez Díaz, María Cristina

    2016-01-01

    [Resumen] Antecedentes y objetivos: La fibrosis miocárdica puede detectarse en la miocardiopatía hipertrófica (MCH) mediante resonancia magnética (RM) con realce tardío de gadolinio. La fibrosis miocárdica y el tamaño de la aurícula izquierda (AI) pueden relacionarse con eventos adversos. Analizamos la relación entre la presencia y extensión del realc...

  17. Attention modulates trans-saccadic integration.

    Science.gov (United States)

    Stewart, Emma E M; Schütz, Alexander C

    2018-01-01

    With every saccade, humans must reconcile the low resolution peripheral information available before a saccade, with the high resolution foveal information acquired after the saccade. While research has shown that we are able to integrate peripheral and foveal vision in a near-optimal manner, it is still unclear which mechanisms may underpin this important perceptual process. One potential mechanism that may moderate this integration process is visual attention. Pre-saccadic attention is a well documented phenomenon, whereby visual attention shifts to the location of an upcoming saccade before the saccade is executed. While it plays an important role in other peri-saccadic processes such as predictive remapping, the role of attention in the integration process is as yet unknown. This study aimed to determine whether the presentation of an attentional distractor during a saccade impaired trans-saccadic integration, and to measure the time-course of this impairment. Results showed that presenting an attentional distractor impaired integration performance both before saccade onset, and during the saccade, in selected subjects who showed integration in the absence of a distractor. This suggests that visual attention may be a mechanism that facilitates trans-saccadic integration. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  18. Mathematical modeling of a radio-frequency path for IEEE 802.11ah based wireless sensor networks

    Science.gov (United States)

    Tyshchenko, Igor; Cherepanov, Alexander; Dmitrii, Vakhnin; Popova, Mariia

    2017-09-01

    This article discusses the process of creating the mathematical model of a radio-frequency path for an IEEE 802.11ah based wireless sensor networks using M atLab Simulink CAD tools. In addition, it describes occurring perturbing effects and determining the presence of a useful signal in the received mixture.

  19. Spectrum-efficient multi-channel design for coexisting IEEE 802.15.4 networks: A stochastic geometry approach

    KAUST Repository

    Elsawy, Hesham

    2014-07-01

    For networks with random topologies (e.g., wireless ad-hoc and sensor networks) and dynamically varying channel gains, choosing the long term operating parameters that optimize the network performance metrics is very challenging. In this paper, we use stochastic geometry analysis to develop a novel framework to design spectrum-efficient multi-channel random wireless networks based on the IEEE 802.15.4 standard. The proposed framework maximizes both spatial and time domain frequency utilization under channel gain uncertainties to minimize the number of frequency channels required to accommodate a certain population of coexisting IEEE 802.15.4 networks. The performance metrics are the outage probability and the self admission failure probability. We relax the single channel assumption that has been used traditionally in the stochastic geometry analysis. We show that the intensity of the admitted networks does not increase linearly with the number of channels and the rate of increase of the intensity of the admitted networks decreases with the number of channels. By using graph theory, we obtain the minimum required number of channels to accommodate a certain intensity of coexisting networks under a self admission failure probability constraint. To this end, we design a superframe structure for the coexisting IEEE 802.15.4 networks and a method for time-domain interference alignment. © 2002-2012 IEEE.

  20. Real-life IT architecture design reports and their relation to IEEE Std 1471 stakeholders and concerns

    NARCIS (Netherlands)

    van Vliet, H.; Koning, H.

    2006-01-01

    Architectural designs are an important means to manage the development and deployment of information technology (IT). Much debate has been going on about a proper definition of architecture in IT and about how to describe it. In 2000, the IEEE Std 1471 proposed a model of an architecture description

  1. Architectural and Functional Design and Evaluation of E-Learning VUIS Based on the Proposed IEEE LTSA Reference Model.

    Science.gov (United States)

    O'Droma, Mairtin S.; Ganchev, Ivan; McDonnell, Fergal

    2003-01-01

    Presents a comparative analysis from the Institute of Electrical and Electronics Engineers (IEEE) Learning Technology Standards Committee's (LTSC) of the architectural and functional design of e-learning delivery platforms and applications, e-learning course authoring tools, and learning management systems (LMSs), with a view of assessing how…

  2. Analyzing the Engineering Educational Research in Spain: A Global Vision through the Awards of CESEI-IEEE

    Science.gov (United States)

    Plaza, I.; Arcega, F.; Castro, M.; Llamas, M.

    2011-01-01

    CESEI is the acronym of the Spanish Chapter of the Education Society of IEEE (the Institute of Electric and Electronics Engineers). Every year, the CESEI awards a prize for the best doctoral thesis and FDP (final (master) degree projects) about education. The thesis or the project must be developed in the areas of electrical engineering,…

  3. Analysis of Radio communication solutions in small and isolated communities under the IEEE 802.22 standard

    OpenAIRE

    Arroyo Arzubi, Alejandro; Castro Lechtaler, Antonio; Foti, Antonio Roberto; Fusario, Rubén J.; García Guibout, Jorge; Sens, Lorena

    2013-01-01

    In recent years the use of wireless communications has increased significantly. Rural communities without cable network communication have found a solution in wireless technologies. Based on previous fieldwork, this paper analyzes software development of integration based technologies for communication equipment. It focuses on the feasibility of the IEEE 802.22 standard as a solution to the wireless problem.

  4. AVSS 2007: IEEE International Conference onAdvanced Video and Signal based Surveillance, London, UK, September 2007

    DEFF Research Database (Denmark)

    Fihl, Preben

    This technical report will cover the participation in the IEEE International Conference on Advanced Video and Signal based Surveillance in September 2007. The report will give a concise description of the most relevant topics presented at the conference, focusing on the work related to the HERMES...... project and human motion and action recognition. Our contribution to the conference will also be described....

  5. Low-cost RAU with Optical Power Supply Used in a Hybrid RoF IEEE 802.11 Network

    Science.gov (United States)

    Kowalczyk, M.; Siuzdak, J.

    2014-09-01

    The paper presents design and implementation of a low-cost RAU (Remote Antenna Unit) device. It was designed to work in a hybrid Wi-Fi/optical network based on the IEEE 802.11b/g standard. An unique feature of the device is the possibility of optical power supply.

  6. Open Data for Global Multimodal Land Use Classification: Outcome of the 2017 IEEE GRSS Data Fusion Contest

    NARCIS (Netherlands)

    Yokoya, Naoto; Ghamisi, Pedram; Xia, Junshi; Sukhanov, Sergey; Heremans, Roel; Tankoyeu, Ivan; Bechtel, Benjamin; Saux, Le Bertrand; Moser, Gabriele; Tuia, Devis

    2018-01-01

    In this paper, we present the scientific outcomes of the 2017 Data Fusion Contest organized by the Image Analysis and Data Fusion Technical Committee of the IEEE Geoscience and Remote Sensing Society. The 2017 Contest was aimed at addressing the problem of local climate zones classification based on

  7. Homologous SV40 RNA trans-splicing: Special case or prime example of viral RNA trans-splicing?

    Directory of Open Access Journals (Sweden)

    Sushmita Poddar

    2014-06-01

    Full Text Available To date the Simian Virus 40 (SV40 is the only proven example of a virus that recruits the mechanism of RNA trans-splicing to diversify its sequences and gene products. Thereby, two identical viral transcripts are efficiently joined by homologous trans-splicing triggering the formation of a highly transforming 100 kDa super T antigen. Sequences of other viruses including HIV-1 and the human adenovirus type 5 were reported to be involved in heterologous trans-splicing towards cellular or viral sequences but the meaning of these events remains unclear. We computationally and experimentally investigated molecular features associated with viral RNA trans-splicing and identified a common pattern: Viral RNA trans-splicing occurs between strong cryptic or regular viral splice sites and strong regular or cryptic splice sites of the trans-splice partner sequences. The majority of these splice sites are supported by exonic splice enhancers. Splice sites that could compete with the trans-splicing sites for cis-splice reactions are weaker or inexistent. Finally, all but one of the trans-splice reactions seem to be facilitated by one or more complementary binding domains of 11 to 16 nucleotides in length which, however occur with a statistical probability close to one for the given length of the involved sequences. The chimeric RNAs generated via heterologous viral RNA trans-splicing either did not lead to fusion proteins or led to proteins of unknown function. Our data suggest that distinct viral RNAs are highly susceptible to trans-splicing and that heterologous viral trans-splicing, unlike homologous SV40 trans-splicing, represents a chance event.

  8. Magnetic resonance imaging and ultrasound in hepatosplenic schistosomiasis mansoni Ressonância magnética e ultrassonografia na esquistossomose mansoni hepatoesplênica

    Directory of Open Access Journals (Sweden)

    José Roberto Lambertucci

    2004-08-01

    Full Text Available We report the findings of abdominal ultrasound and magnetic resonance imaging observed in a patient with advanced schistosomiasis mansoni. A 25-year-old man with hepatosplenic schistosomiasis and variceal bleeding confirmed by upper endoscopy was submitted to abdominal ultrasound and magnetic resonance imaging. During surgery for portal hypertension, a liver biopsy was taken and the diagnosis of Symmers' fibrosis was confirmed. magnetic resonance imaging scans gave more precise information about the gallbladder, periportal thickening and abdominal venous system than did the ultrasound.Relatamos os achados ultrassonográficos e à ressonância magnética intra-abdominais observados em um paciente com esquistossomose mansoni grave. Um homem de 25 anos de idade com esquistossomose hepatoesplênica e sangramento digestivo de varizes esofagianas, com diagnóstico confirmado pela endoscopia, foi submetido à ultrasonografia abdominal e ressonância magnética. Durante a cirurgia de hipertensão porta, um fragmento de fígado foi obtido e o exame histológico confirmou o diagnóstico de fibrose de Symmers. A ressonância magnética forneceu informações mais precisas sobre a vesícula biliar, espessamento periportal e sistema venoso abdominal do que a ultrassonografia.

  9. Magneli phase Ti4O7 electrode for oxygen reduction reaction and its implication for zinc-air rechargeable batteries

    International Nuclear Information System (INIS)

    Li Xiaoxia; Zhu, Aaron Li; Qu Wei; Wang Haijiang; Hui, Rob; Zhang Lei; Zhang Jiujun

    2010-01-01

    In this paper, Magneli phase Ti 4 O 7 was successfully synthesized using a TiO 2 reduction method, and characterized using X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The electrode coated with this Ti 4 O 7 material showed activities for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). For the ORR, several parameters, including overall electron transfer number, kinetic constants, electron transfer coefficient, and percentage H 2 O 2 production, were obtained using the rotating ring-disk electrode (RRDE) technique and the Koutecky-Levich theory. The overall electron transfer number was found to be between 2.3 and 2.9 in 1, 4, and 6 M KOH electrolytes, suggesting that the ORR process on the Ti 4 O 7 electrode was a mixed process of 2- and 4-electron transfer pathways. Electrochemical durability tests, carried out in highly concentrated KOH electrolyte, confirmed that this Ti 4 O 7 is a stable electrode material, suggesting that it should be a feasible candidate for the air-cathodes of zinc-air batteries. To understand the stability of this material, Raman and XPS spectra were also collected for the Ti 4 O 7 samples before and after the stability tests. The results and analysis revealed that a thin layer of TiO 2 formed on the Ti 4 O 7 surface, which may have prevented further oxidation into the bulk of the Ti 4 O 7 electrode.

  10. Síndrome de Hallervorden Spatz: achados na resonância magnética. Relato de caso

    Directory of Open Access Journals (Sweden)

    Farage Luciano

    2004-01-01

    Full Text Available A síndrome de Hallervorden-Spatz é afecção neurodegenerativa, autossômica recessiva com duas apresentações clínicas: precoce e tardia. Esta última é caracterizada pelo acometimento psiquiátrico e a presença de sinais piramidais e extrapiramidais. Relatamos o caso de mulher de 41 anos, com história de alterações extrapiramidais. O exame de ressonância magnética (RM mostrou o sinal dos olhos-de-tigre, lesão dos globos pálidos mediais com deposição de ferro periférica (hipo-sinal e gliose central (hipersinal, nas seqüências com tempo de repetição (TR longo. Há forte relação entre o sinal na RM e mutações no gene responsável pela lesão, fazendo deste exame sensível o suficiente para a realização do diagnóstico da doença.

  11. Marquage magnétique interne : essais de tolérance par de jeunes saumons atlantiques (Salmo salar L.

    Directory of Open Access Journals (Sweden)

    DUMAS J.

    1982-10-01

    Full Text Available Les effets de l'implantation d'une marque magnétique "Metalimphy" * de 20 x 1,5 mm dans la cavité abdominale de jeunes saumons d'élevage sont comparés à ceux d'un marquage classique par ablation de la nageoire adipeuse. Les essais sont effectués sur des tacons de deuxième été et des pré-saumoneaux d'un an dans deux piscicultures de Bretagne et des Pyrénées-Atlantiques. Quel que soit le mode d'insertion pratiqué (ventral ou latéral cette technique n'a aucun effet significatif sur la survie et la croissance des poissons, qu'ils soient tacons (observés sur 194 jours ou pré-saumoneaux (observés sur 56 jours. La cicatrisation est rapide et ce marquage n'entrave pas la smoltification. L'emploi d'une poudre antibiotique cicatrisante ne semble pas nécessaire en conditions normales de pisciculture. L'insertion par voie ventrale s'avère préférable à l'insertion latérale ; elle n'entraîne pas de pertes de marques et se révèle plus facile à pratiquer.

  12. FROM ADVANCE TO TRANS-PROFESSIONAL EDUCATION

    Directory of Open Access Journals (Sweden)

    A. G. Kislov

    2018-01-01

    Full Text Available Introduction. For several decades, the gap of vocational education with quickly changing realities in labour market, in the field of technologies and socio-economic sphere, and the need for the advancing vocational training, have been considered as the topical and steadily growing problems. Numerous attempts to overcome the presented above problems by means of fundamentalization and predictive methods have not led to anything so far. It is obvious that other education opportunities for in-demand, highly skilled, competitive specialists are needed.The aims of the publication are to discuss the potential of trans-professional education; to come up with arguments in favour of its introduction as the most perspective direction which might allow university and college graduates: to be guided better on labour market; to be more confident in unstable, unpredictable reality; to adapt quickly to dynamically changing situations in the world of professions.Methodology and research methods. The research paper is based on comparative analysis that provided an opportunity to find out the conceptual grounds of traditional mono-professional education and trans-professional education appropriate for challenges of modern Russia.Results and scientific novelty. It is emphasized that mono-professionalism as a paradigm reference point of professional education content is called for global reconsideration; for many years, preservation of traditional forms and methods have prevented mono-professionalism of good intentions to give it the advancing character, especially, at its initial stage.For the first time, trans-professional education has been considered as a result of considerably heterogeneous (as opposed to homogeneous bi- and polyprofessional training; the essence of that training consists in learning not related specialties concerned to one professional group, but professions that are absolutely far apart. Such approach will promote not only expansion of

  13. Repair Activity of trans-Resveratrol toward 2'-Deoxyguanosine Radicals.

    Science.gov (United States)

    Cheng, Xing; An, Ping; Li, Shujin; Zhou, Liping

    2018-04-26

    In the present study, the repair activity of trans-resveratrol toward 2'-deoxyguanosine (dGuo) radicals in polar and nonpolar solvents was studied using density functional theory. The hydrogen transfer/proton coupled electron transfer and single electron transfer (SET) mechanisms between trans-resveratrol and dGuo-radicals were considered. Taking into consideration the molar fraction of neutral trans-resveratrol (ROH) and anionic trans-resveratrol (RO - ), the overall rate constants for repairing dGuo-radicals by trans-resveratrol are 9.94 × 10 8 and 2.01 × 10 9 dm 3 mol -1 s -1 in polar and nonpolar solvents, respectively, and the overall rate constant of repairing cation radical (dGuo •+ ) by trans-resveratrol via an SET mechanism is 7.17 × 10 9 dm 3 mol -1 s -1 . The repair activity of RO - toward dGuo-radicals is better than that of ROH, but the repair activity of ROH toward dGuo •+ is better than that of RO - . Unfortunately, neither ROH nor RO - can repair the 2'-deoxyribose radicals of dGuo. It can therefore be concluded that trans-resveratrol is an effective antioxidant for repairing base radicals of dGuo and dGuo •+ . The study can help us understand the repair activity of trans-resveratrol toward dGuo radicals.

  14. Shifting Paradigms: Moving beyond "Trans 101" in Sexuality Education

    Science.gov (United States)

    Green, Eli R.

    2010-01-01

    Trans-inclusive sexuality education can be complex, confusing, and outright intimidating for even the most seasoned sexuality educator to teach. Historically, standalone "Trans 101" sessions have successfully raised awareness about the highly marginalized transgender community. However, their potential success has been limited by being taught in…

  15. Illela border market: origin and contributions to trans-border ...

    African Journals Online (AJOL)

    Illela border market: origin and contributions to trans-border relations between Nigeria and Niger republic. ... cordial relations between her and her immediate neighbours and thus stem the scourge of smuggling and other trans-border crimes which have negatively affected the Nigerian economy and her international image.

  16. TransPlanckian Particles and the Quantization of Time

    NARCIS (Netherlands)

    Hooft, G. 't

    1999-01-01

    Trans-Planckian particles are elementary particles accelerated such that their energies surpass the Planck value. There are several reasons to believe that trans-Planckian particles do not represent independent degrees of freedom in Hilbert space, but they are controlled by the cis-Planckian

  17. Relative Stability of cis- and trans-Hydrindanones

    Directory of Open Access Journals (Sweden)

    Motoo Tori

    2015-01-01

    Full Text Available The relative stabilities of several cis- and trans-hydrindanones were compared using both isomerization experiments and MM2 calculations. The generally believed rule that cis-hydrindanones are more stable than trans-isomers is applicable, but is not always true. This review introduces examples, mainly from studies in our laboratory, to explain these facts.

  18. Survey of the trans-resveratrol and trans-piceid content of cocoa-containing and chocolate products.

    Science.gov (United States)

    Hurst, W Jeffrey; Glinski, Jan A; Miller, Kenneth B; Apgar, Joan; Davey, Matthew H; Stuart, David A

    2008-09-24

    Dietary resveratrol (3,4',5-trihydroxystilbene) has been implicated in the health benefits associated with grapes and red wine, more specifically with potential benefits for metabolic syndrome, energy use, and increased endurance. Levels of trans-resveratrol and its glucoside, trans-piceid, were determined in 19 top selling commercially available cocoa-containing and chocolate products from the U.S. market. Amounts of trans-resveratrol and trans-piceid were closely correlated with the amount of nonfat cocoa solids (NFCS) in the cocoa-containing products. Among these products, trans-resveratrol levels were highest in cocoa powders (1.85 +/- 0.43 microg/g), followed by unsweetened baking chocolates (1.24 +/- 0.22), semisweet chocolate baking chips (0.52 +/- 0.14), dark chocolates (0.35 +/- 0.08), milk chocolates (0.10 +/- 0.05), and chocolate syrups (0.09 +/- 0.02). These cocoa-containing and chocolate products have about 3-5 times more trans-piceid than trans-resveratrol. Levels of trans-piceid were highest in the cocoa powders (7.14 +/- 0.80 microg/g), followed by unsweetened baking chocolates (4.04 +/- 0.14), semisweet chocolate baking chips (2.01 +/- 0.18), dark chocolates (1.82 +/- 0.36), milk chocolates (0.44 +/- 0.06), and chocolate syrups (0.35 +/- 0.06). On an equal weight basis, cocoa powder had about half as much trans-resveratrol as the average California red wine. On a per serving basis, cocoa-containing and chocolate products had less trans-resveratrol than red wine and grape juice but more than roasted peanuts. Overall, these cocoa-containing and chocolate products rank second after red wines and grape juice in foods with the highest levels of total trans-resveratrol in the diet.

  19. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The objects of this invention are first to reduce the time required to obtain statistically significant data in trans-axial tomographic radioisotope scanning using a scintillation camera. Secondly, to provide a scintillation camera system to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a known radiation source without sacrificing spatial resolution. Thirdly to reduce the scanning time without loss of image clarity. The system described comprises a scintillation camera detector, means for moving this in orbit about a cranial-caudal axis relative to a patient and a collimator having septa defining apertures such that gamma rays perpendicular to the axis are admitted with high spatial resolution, parallel to the axis with low resolution. The septa may be made of strips of lead. Detailed descriptions are given. (U.K.)

  20. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The principal problem in trans-axial tomographic radioisotope scanning is the length of time required to obtain meaningful data. Patient movement and radioisotope migration during the scanning period can cause distortion of the image. The object of this invention is to reduce the scanning time without degrading the images obtained. A system is described in which a scintillation camera detector is moved to an orbit about the cranial-caudal axis relative to the patient. A collimator is used in which lead septa are arranged so as to admit gamma rays travelling perpendicular to this axis with high spatial resolution and those travelling in the direction of the axis with low spatial resolution, thus increasing the rate of acceptance of radioactive events to contribute to the positional information obtainable without sacrificing spatial resolution. (author)

  1. Trans Ocean Gas CNG transportation development plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-11-01

    Liquefied natural gas (LNG) transportation is on the rise due to increased global demand for natural gas. However, the challenge of transporting LNG lies in finding suitable locations for import terminals. Compressed natural gas (CNG) transportation offers an alternative method for transporting stranded natural gas to existing markets and for creating new natural gas markets not practical for LNG or pipelines. The founder of Trans Ocean Gas Inc. (TOG) modified an existing fibre reinforced plastic (FRP) pressure vessel technology to safely store CNG on a ship. The newly developed containment system has proven to overcome all the deficiencies of steel-based systems. TOG patented the containment system and will license its use to owners of stranded gas and shipping service providers around the world. Financial support is needed to perform verification testing and for regulatory approval. The CNG systems will be built and assembled throughout facilities in Atlantic Canada. 2 tabs., 3 figs.

  2. Exploring the Trans-Neptunian Solar System

    Science.gov (United States)

    1998-01-01

    A profound question for scientists, philosophers and, indeed, all humans concerns how the solar system originated and subsequently evolved. To understand the solar system's formation, it is necessary to document fully the chemical and physical makeup of its components today, particularly those parts thought to retain clues about primordial conditions and processes.] In the past decade, our knowledge of the outermost, or trans-neptunian, region of the solar system has been transformed as a result of Earth-based observations of the Pluto-Charon system, Voyager 2's encounter with Neptune and its satellite Triton, and recent discoveries of dozens of bodies near to or beyond the orbit of Neptune. As a class, these newly detected objects, along with Pluto, Charon, and Triton, occupy the inner region of a hitherto unexplored component of the solar system, the Kuiper Belt. The Kuiper Belt is believed to be a reservoir of primordial objects of the type that formed in the solar nebula and eventually accreted to form the major planets. The Kuiper Belt is also thought to be the source of short-period comets and a population of icy bodies, the Centaurs, with orbits among the giant planets. Additional components of the distant outer solar system, such as dust and the Oort comet cloud, as well as the planet Neptune itself, are not discussed in this report. Our increasing knowledge of the trans-neptunian solar system has been matched by a corresponding increase in our capabilities for remote and in situ observation of these distant regions. Over the next 10 to 15 years, a new generation of ground- and space-based instruments, including the Keck and Gemini telescopes and the Space Infrared Telescope Facility, will greatly expand our ability to search for and conduct physical and chemical studies on these distant bodies. Over the same time span, a new generation of lightweight spacecraft should become available and enable the first missions designed specifically to explore the icy

  3. Real-Time Station Grouping under Dynamic Traffic for IEEE 802.11ah.

    Science.gov (United States)

    Tian, Le; Khorov, Evgeny; Latré, Steven; Famaey, Jeroen

    2017-07-04

    IEEE 802.11ah, marketed as Wi-Fi HaLow, extends Wi-Fi to the sub-1 GHz spectrum. Through a number of physical layer (PHY) and media access control (MAC) optimizations, it aims to bring greatly increased range, energy-efficiency, and scalability. This makes 802.11ah the perfect candidate for providing connectivity to Internet of Things (IoT) devices. One of these new features, referred to as the Restricted Access Window (RAW), focuses on improving scalability in highly dense deployments. RAW divides stations into groups and reduces contention and collisions by only allowing channel access to one group at a time. However, the standard does not dictate how to determine the optimal RAW grouping parameters. The optimal parameters depend on the current network conditions, and it has been shown that incorrect configuration severely impacts throughput, latency and energy efficiency. In this paper, we propose a traffic-adaptive RAW optimization algorithm (TAROA) to adapt the RAW parameters in real time based on the current traffic conditions, optimized for sensor networks in which each sensor transmits packets with a certain (predictable) frequency and may change the transmission frequency over time. The TAROA algorithm is executed at each target beacon transmission time (TBTT), and it first estimates the packet transmission interval of each station only based on packet transmission information obtained by access point (AP) during the last beacon interval. Then, TAROA determines the RAW parameters and assigns stations to RAW slots based on this estimated transmission frequency. The simulation results show that, compared to enhanced distributed channel access/distributed coordination function (EDCA/DCF), the TAROA algorithm can highly improve the performance of IEEE 802.11ah dense networks in terms of throughput, especially when hidden nodes exist, although it does not always achieve better latency performance. This paper contributes with a practical approach to optimizing

  4. Performance Evaluation of IEEE 802.11ah Networks With High-Throughput Bidirectional Traffic.

    Science.gov (United States)

    Šljivo, Amina; Kerkhove, Dwight; Tian, Le; Famaey, Jeroen; Munteanu, Adrian; Moerman, Ingrid; Hoebeke, Jeroen; De Poorter, Eli

    2018-01-23

    So far, existing sub-GHz wireless communication technologies focused on low-bandwidth, long-range communication with large numbers of constrained devices. Although these characteristics are fine for many Internet of Things (IoT) applications, more demanding application requirements could not be met and legacy Internet technologies such as Transmission Control Protocol/Internet Protocol (TCP/IP) could not be used. This has changed with the advent of the new IEEE 802.11ah Wi-Fi standard, which is much more suitable for reliable bidirectional communication and high-throughput applications over a wide area (up to 1 km). The standard offers great possibilities for network performance optimization through a number of physical- and link-layer configurable features. However, given that the optimal configuration parameters depend on traffic patterns, the standard does not dictate how to determine them. Such a large number of configuration options can lead to sub-optimal or even incorrect configurations. Therefore, we investigated how two key mechanisms, Restricted Access Window (RAW) grouping and Traffic Indication Map (TIM) segmentation, influence scalability, throughput, latency and energy efficiency in the presence of bidirectional TCP/IP traffic. We considered both high-throughput video streaming traffic and large-scale reliable sensing traffic and investigated TCP behavior in both scenarios when the link layer introduces long delays. This article presents the relations between attainable throughput per station and attainable number of stations, as well as the influence of RAW, TIM and TCP parameters on both. We found that up to 20 continuously streaming IP-cameras can be reliably connected via IEEE 802.11ah with a maximum average data rate of 160 kbps, whereas 10 IP-cameras can achieve average data rates of up to 255 kbps over 200 m. Up to 6960 stations transmitting every 60 s can be connected over 1 km with no lost packets. The presented results enable the fine tuning

  5. Becoming lesbian: Monique Wittig's queer-trans-feminism.

    Science.gov (United States)

    Henderson, Kevin

    2018-04-03

    Inspired by Lynne Huffer's queer feminist genealogy, this article explores queer-trans-feminism as a project that would bring together queer, feminist, and transgender theory and politics into a shared critical lineage. I suggest that Monique Wittig is a neglected thinker who could re-enliven connections and debates within queer, feminist, and trans theory and politics. Utilizing recent historiographies of queer and feminist theory, I imagine what it would mean to hold on to the figure of the lesbian as a figure for queer-trans-feminist politics rather than render the lesbian anachronistic. I then explore the implications of Wittig's notion that "lesbians are not women" for a queer-trans-feminism. I argue that Wittig's critique of the language of the social sciences offers queer-trans-feminist scholars a source for contemporary self-critique and coalition.

  6. Acetylcholinesterase Inhibition and Antioxidant Activity of N-trans-Caffeoyldopamine and N-trans-Feruloyldopamine

    Directory of Open Access Journals (Sweden)

    Muamer Dizdar

    2018-04-01

    Full Text Available Phenolic acids and their derivatives found in nature are well-known for their potential biological activity. In this study, two amides derived from trans-caffeic/ferulic acid and dopamine were synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR, mass spectrometry, proton and carbon-13 nuclear magnetic resonance spectroscopy. The compounds were tested for the inhibition of acetylcholinesterase (AChE from Electrophorus electricus and for antioxidant activity by scavenging 2,2-diphenyl-1-pycrylhydrazyl free radical (DPPH• and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS•+, reducing ferric ions, and ferrous ions chelation. N-trans-Feruloyldopamine displayed the highest inhibitory effect on AChE with half-maximal inhibitory concentration (IC50 values of 8.52 μM. In addition, an in silico study was done to determine the most favorable AChE cluster with the synthesized compounds. Further, these clusters were investigated for binding positions at the lowest free binding energy. Both synthesized hydroxycinnamates were found to be better antioxidants than the parent acids in in vitro tests applied. N-trans-Caffeoyldopamine showed the best antioxidant activity in the three tested methods—against non-biological stable free radicals IC50 5.95 μM for DPPH•, 0.24 μM for the ABTS•+ method, and for reducing power (ascorbic acid equivalent (AAE 822.45 μmol/mmol—while for chelation activity against Fe2+ ions N-trans-feruloyldopamine had slightly better antioxidant activity (IC50 3.17 mM.

  7. Understanding the complexity of trans fatty acid reduction in the American diet: American Heart Association Trans Fat Conference 2006: report of the Trans Fat Conference Planning Group.

    Science.gov (United States)

    Eckel, Robert H; Borra, Susan; Lichtenstein, Alice H; Yin-Piazza, Shirley Y

    2007-04-24

    A 2-day forum was convened to discuss the current status and future implications of reducing trans fatty acids without increasing saturated fats in the food supply while maintaining functionality and consumer acceptance of packaged, processed, and prepared foods. Attendees represented the agriculture and oilseed industry and oil processing, food manufacturing, food service, government, food technology, and health and nutrition disciplines. Presentations included food science behind fatty acid technology, the health science of dietary fatty acids, alternatives to trans fatty acids, and the use of alternatives in food manufacturing and food service. The reduction of trans fatty acids in the food supply is a complex issue involving interdependent and interrelated stakeholders. Actions to reduce trans fatty acids need to carefully consider both intended and unintended consequences related to nutrition and public health. The unintended consequence of greatest concern is that fats and oils high in saturated fats, instead of the healthier unsaturated fats, might be used to replace fats and oils with trans fatty acids. Many different options of alternative oils and fats to replace trans fatty acids are available or in development. Decisions on the use of these alternatives need to consider availability, health effects, research and development investments, reformulated food quality and taste, supply-chain management, operational modifications, consumer acceptance, and cost. The conference demonstrated the value of collaboration between the food industry and health and nutrition professionals, and this conference model should be used to address other food development, processing, and/or technology issues.

  8. Micro-Sugar-Snap and -Wire-Cut Cookie Baking with Trans- and Zero-Trans-Fat Shortenings

    Science.gov (United States)

    The effect of trans- and zero-trans-fat shortenings on cookie-baking performance was evaluated, using the two AACC micro-cookie-baking methods. Regardless of fat type, sugar-snap cookies made with a given flour were larger in diameter, smaller in height, and greater in weight loss during baking tha...

  9. An empirical evaluation of bufferbloat in IEEE 802.11n wireless networks

    KAUST Repository

    Showail, Ahmad

    2014-04-06

    In this paper, we analyze the impact of large, persistently-full buffers (`bufferbloat\\') on various network dynamics in IEEE 802.11n wireless networks. Bufferbloat has mostly been studied in the context of wired networks. We study the impact of bufferbloat on a variety of wireless network topologies, including wireless LAN (WLAN) and multi-hop wireless networks. Our results show that a single FTP transfer between two Linux wireless hosts can saturate the buffers in the network stack, leading to RTT delays exceeding 4.5 s in multi-hop configurations. We show that well-designed Aggregate MAC Protocol Data Unit (A-MPDU) MAC-layer frame aggregation can reduce RTT delays while simultaneously increasing network throughput. However, additional measures may still be required to meet the constraints of real-time flows (such as VoIP). Our experiments show that large buffers can deteriorate the fairness in rate allocation in parking lot based multi-hop networks.

  10. Green Frame Aggregation Scheme for IEEE 802.11n Networks

    KAUST Repository

    Alaslani, Maha S.

    2015-04-01

    Frame aggregation is one of the major MAC layer enhancements in the IEEE 802.11 family that boosts the network throughput performance. It aims to achieve higher throughput by transmitting huge amount of data in a single transmit oppor- tunity. With the increasing awareness of energy e ciency, it has become vital to rethink about the design of such frame aggregation protocol. Aggregation techniques help to reduce energy consumption over ideal channel conditions. However, in a noisy channel environment, a new energy-aware frame aggregation scheme is required. In this thesis, a novel Green Frame Aggregation (GFA) scheduling scheme has been proposed and evaluated. GFA optimizes the aggregate size based on channel quality in order to minimize the consumed energy. GFA selects the optimal sub-frame size that satisfies the loss constraint for real-time applications as well as the energy budget of the ideal channel situations. The design, the implementation, and evaluation of GFA using testbed deployment is done. The experimental analysis shows that GFA outperforms the conventional frame aggregation methodology in terms of energy e ciency by about 6⇥ in the presence of severe interference conditions. Moreover, GFA also outperforms the static frame sizing method in terms of network goodput and maintains almost the same end- to-end latency.

  11. Smart City Pilot Projects Using LoRa and IEEE802.15.4 Technologies.

    Science.gov (United States)

    Pasolini, Gianni; Buratti, Chiara; Feltrin, Luca; Zabini, Flavio; De Castro, Cristina; Verdone, Roberto; Andrisano, Oreste

    2018-04-06

    Information and Communication Technologies (ICTs), through wireless communications and the Internet of Things (IoT) paradigm, are the enabling keys for transforming traditional cities into smart cities, since they provide the core infrastructure behind public utilities and services. However, to be effective, IoT-based services could require different technologies and network topologies, even when addressing the same urban scenario. In this paper, we highlight this aspect and present two smart city testbeds developed in Italy. The first one concerns a smart infrastructure for public lighting and relies on a heterogeneous network using the IEEE 802.15.4 short-range communication technology, whereas the second one addresses smart-building applications and is based on the LoRa low-rate, long-range communication technology. The smart lighting scenario is discussed providing the technical details and the economic benefits of a large-scale (around 3000 light poles) flexible and modular implementation of a public lighting infrastructure, while the smart-building testbed is investigated, through measurement campaigns and simulations, assessing the coverage and the performance of the LoRa technology in a real urban scenario. Results show that a proper parameter setting is needed to cover large urban areas while maintaining the airtime sufficiently low to keep packet losses at satisfactory levels.

  12. IEEE 802.11-Based Wireless Sensor System for Vibration Measurement

    Directory of Open Access Journals (Sweden)

    Yutaka Uchimura

    2010-01-01

    Full Text Available Network-based wireless sensing has become an important area of research and various new applications for remote sensing are expected to emerge. One of the promising applications is structural health monitoring of building or civil engineering structure and it often requires vibration measurement. For the vibration measurement via wireless network, time synchronization is indispensable. In this paper, we introduce a newly developed time synchronized wireless sensor network system. The system employs IEEE 802.11 standard-based TSF-counter and sends the measured data with the counter value. TSF based synchronization enables consistency on common clock among different wireless nodes. We consider the scale effect on synchronization accuracy and evaluated the effect by taking beacon collisions into account. The scalability issue by numerical simulations is also studied. This paper also introduces a newly developed wireless sensing system and the hardware and software specifications are introduced. The experiments were conducted in a reinforced concrete building to evaluate synchronization accuracy. The developed system was also applied for a vibration measurement of a 22-story steel structured high rise building. The experimental results showed that the system performed more than sufficiently.

  13. The Impact of Dynamic RTS Threshold Adjustment for IEEE 802.11 MAC Protocol

    Directory of Open Access Journals (Sweden)

    Mostafa Mjidi

    2009-01-01

    Full Text Available In recent years, wireless technologies and application received great attention. The Medium Access Control (MAC protocol is the main element that determines the efficiency in sharing the limited communication bandwidth of the wireless channel in wireless local area networks (WLANs. IEEE 802.11 introduced the optional RTS/CTS handshaking mechanism to address the hidden terminal problem as well as to reduces the chance of collision in case of higher node density and traffic. RTS Threshold (RT determines when RTS/CTS mechanism should be used and proved to be an important parameter for performance characteristics in data transmission. We first investigate to find a meaningful threshold value according to the network situation and determine the impact of using or disengaging the RTS/CTS optional mechanism and dynamically adjust the RTS Threshold to maximize data transmission. The results show a significant improvement over existing CSMA/CA and RTS/CTS schemes. Our adaptive scheme performed even better when data rate increases. We verify our proposed scheme both analytically and with extensive network simulation using ns-2.

  14. An empirical evaluation of bufferbloat in IEEE 802.11n wireless networks

    KAUST Repository

    Showail, Ahmad; Jamshaid, Kamran; Shihada, Basem

    2014-01-01

    In this paper, we analyze the impact of large, persistently-full buffers (`bufferbloat') on various network dynamics in IEEE 802.11n wireless networks. Bufferbloat has mostly been studied in the context of wired networks. We study the impact of bufferbloat on a variety of wireless network topologies, including wireless LAN (WLAN) and multi-hop wireless networks. Our results show that a single FTP transfer between two Linux wireless hosts can saturate the buffers in the network stack, leading to RTT delays exceeding 4.5 s in multi-hop configurations. We show that well-designed Aggregate MAC Protocol Data Unit (A-MPDU) MAC-layer frame aggregation can reduce RTT delays while simultaneously increasing network throughput. However, additional measures may still be required to meet the constraints of real-time flows (such as VoIP). Our experiments show that large buffers can deteriorate the fairness in rate allocation in parking lot based multi-hop networks.

  15. On the Optimization of the IEEE 802.11 DCF: A Cross-Layer Perspective

    Directory of Open Access Journals (Sweden)

    Massimiliano Laddomada

    2010-01-01

    Full Text Available This paper is focused on the problem of optimizing the aggregate throughput of the distributed coordination function (DCF employing the basic access mechanism at the data link layer of IEEE 802.11 protocols. We consider general operating conditions accounting for both nonsaturated and saturated traffic in the presence of transmission channel errors, as exemplified by the packet error rate . The main clue of this work stems from the relation that links the aggregate throughput of the network to the packet rate of the contending stations. In particular, we show that the aggregate throughput ( presents two clearly distinct operating regions that depend on the actual value of the packet rate with respect to a critical value , theoretically derived in this work. The behavior of ( paves the way to a cross-layer optimization algorithm, which proved to be effective for maximizing the aggregate throughput in a variety of network operating conditions. A nice consequence of the proposed optimization framework relies on the fact that the aggregate throughput can be predicted quite accurately with a simple, yet effective, closed-form expression. Finally, theoretical and simulation results are presented in order to unveil, as well as verify, the key ideas.

  16. An SNMP-based solution to enable remote ISO/IEEE 11073 technical management.

    Science.gov (United States)

    Lasierra, Nelia; Alesanco, Alvaro; García, José

    2012-07-01

    This paper presents the design and implementation of an architecture based on the integration of simple network management protocol version 3 (SNMPv3) and the standard ISO/IEEE 11073 (X73) to manage technical information in home-based telemonitoring scenarios. This architecture includes the development of an SNMPv3-proxyX73 agent which comprises a management information base (MIB) module adapted to X73. In the proposed scenario, medical devices (MDs) send information to a concentrator device [designated as compute engine (CE)] using the X73 standard. This information together with extra information collected in the CE is stored in the developed MIB. Finally, the information collected is available for remote access via SNMP connection. Moreover, alarms and events can be configured by an external manager in order to provide warnings of irregularities in the MDs' technical performance evaluation. This proposed SNMPv3 agent provides a solution to integrate and unify technical device management in home-based telemonitoring scenarios fully adapted to X73.

  17. New IEEE 11073 Standards for interoperable, networked Point-of-Care Medical Devices.

    Science.gov (United States)

    Kasparick, Martin; Schlichting, Stefan; Golatowski, Frank; Timmermann, Dirk

    2015-08-01

    Surgical procedures become more and more complex and the number of medical devices in an operating room (OR) increases continuously. Today's vendor-dependent solutions for integrated ORs are not able to handle this complexity. They can only form isolated solutions. Furthermore, high costs are a result of vendor-dependent approaches. Thus we present a service-oriented device communication for distributed medical systems that enables the integration and interconnection between medical devices among each other and to (medical) information systems, including plug-and-play functionality. This system will improve patient's safety by making technical complexity of a comprehensive integration manageable. It will be available as open standards that are part of the IEEE 11073 family of standards. The solution consists of a service-oriented communication technology, the so called Medical Devices Profile for Web Services (MDPWS), a Domain Information & Service Model, and a binding between the first two mechanisms. A proof of this concept has been done with demonstrators of real world OR devices.

  18. IEEE-802.15.4-based low-power body sensor node with RF energy harvester.

    Science.gov (United States)

    Tran, Thang Viet; Chung, Wan-Young

    2014-01-01

    This paper proposes the design and implementation of a low-voltage and low-power body sensor node based on the IEEE 802.15.4 standard to collect electrocardiography (ECG) and photoplethysmography (PPG) signals. To achieve compact size, low supply voltage, and low power consumption, the proposed platform is integrated into a ZigBee mote, which contains a DC-DC booster, a PPG sensor interface module, and an ECG front-end circuit that has ultra-low current consumption. The input voltage of the proposed node is very low and has a wide range, from 0.65 V to 3.3 V. An RF energy harvester is also designed to charge the battery during the working mode or standby mode of the node. The power consumption of the proposed node reaches 14 mW in working mode to prolong the battery lifetime. The software is supported by the nesC language under the TinyOS environment, which enables the proposed node to be easily configured to function as an individual health monitoring node or a node in a wireless body sensor network (BSN). The proposed node is used to set up a wireless BSN that can simultaneously collect ECG and PPG signals and monitor the results on the personal computer.

  19. An Enhanced Reservation-Based MAC Protocol for IEEE 802.15.4 Networks

    Science.gov (United States)

    Afonso, José A.; Silva, Helder D.; Macedo, Pedro; Rocha, Luis A.

    2011-01-01

    The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and support to a maximum of only seven devices. This paper presents eLPRT (enhanced Low Power Real Time), a new reservation-based MAC protocol that introduces several performance enhancing features in comparison to the GTS scheme. This MAC protocol builds on top of LPRT (Low Power Real Time) and includes various mechanisms designed to increase data transmission reliability against channel errors, improve bandwidth utilization and increase the number of supported devices. A motion capture system based on inertial and magnetic sensors has been used to validate the protocol. The effectiveness of the performance enhancements introduced by each of the new features is demonstrated through the provision of both simulation and experimental results. PMID:22163826

  20. Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests.

    Science.gov (United States)

    Ding, Xingjian; Sun, Guodong; Yang, Gaoxiang; Shang, Xinna

    2016-06-27

    Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments.

  1. On the Feasibility of Wireless Multimedia Sensor Networks over IEEE 802.15.5 Mesh Topologies.

    Science.gov (United States)

    Garcia-Sanchez, Antonio-Javier; Losilla, Fernando; Rodenas-Herraiz, David; Cruz-Martinez, Felipe; Garcia-Sanchez, Felipe

    2016-05-05

    Wireless Multimedia Sensor Networks (WMSNs) are a special type of Wireless Sensor Network (WSN) where large amounts of multimedia data are transmitted over networks composed of low power devices. Hierarchical routing protocols typically used in WSNs for multi-path communication tend to overload nodes located within radio communication range of the data collection unit or data sink. The battery life of these nodes is therefore reduced considerably, requiring frequent battery replacement work to extend the operational life of the WSN system. In a wireless sensor network with mesh topology, any node may act as a forwarder node, thereby enabling multiple routing paths toward any other node or collection unit. In addition, mesh topologies have proven advantages, such as data transmission reliability, network robustness against node failures, and potential reduction in energy consumption. This work studies the feasibility of implementing WMSNs in mesh topologies and their limitations by means of exhaustive computer simulation experiments. To this end, a module developed for the Synchronous Energy Saving (SES) mode of the IEEE 802.15.5 mesh standard has been integrated with multimedia tools to thoroughly test video sequences encoded using H.264 in mesh networks.

  2. Low-power secure body area network for vital sensors toward IEEE802.15.6.

    Science.gov (United States)

    Kuroda, Masahiro; Qiu, Shuye; Tochikubo, Osamu

    2009-01-01

    Many healthcare/medical services have started using personal area networks, such as Bluetooth and ZigBee; these networks consist of various types of vital sensors. These works focus on generalized functions for sensor networks that expect enough battery capacity and low-power CPU/RF (Radio Frequency) modules, but less attention to easy-to-use privacy protection. In this paper, we propose a commercially-deployable secure body area network (S-BAN) with reduced computational burden on a real sensor that has limited RAM/ROM sizes and CPU/RF power consumption under a light-weight battery. Our proposed S-BAN provides vital data ordering among sensors that are involved in an S-BAN and also provides low-power networking with zero-administration security by automatic private key generation. We design and implement the power-efficient media access control (MAC) with resource-constraint security in sensors. Then, we evaluate the power efficiency of the S-BAN consisting of small sensors, such as an accessory type ECG and ring-type SpO2. The evaluation of power efficiency of the S-BAN using real sensors convinces us in deploying S-BAN and will also help us in providing feedbacks to the IEEE802.15.6 MAC, which will be the standard for BANs.

  3. TCP Performance in Multi-Polling Game Theory-Based IEEE 802.11 Networks

    Directory of Open Access Journals (Sweden)

    Cuzanauskas Tomas

    2016-12-01

    Full Text Available Easy usage and integration with various applications made IEEE 802.11 one of the most used technologies these days, both at home and business premises. Over the years, there have been many additional improvements to the 802.11 standards. Nevertheless, the algorithms and Media Access Control (MAC layer methods are almost the same as in previous Wi-Fi versions. In this paper, a set of methods to improve the total system capacity is proposed – such as efficient transmit power management based on Game Theory with a custom wireless medium protocol. The transmit power management and wireless medium protocol is verified by both simulation and real application scenarios. The results conclude that the capacity of the proposed wireless medium protocol is overall 20 percent higher than the standard 802.11 wireless medium access protocols. Additional TCP Acknowledgment filtering, which was tested together with the proposed wireless medium access protocol, can provide up to 10-percent-higher TCP throughput in high-density scenarios, especially for asymmetrical traffic cases. The conducted research suggests that efficient power management could result in lighter transmit power allocation rules that are currently set by the local regulators for current Wi-Fi devices. Thus, better propagation characteristics and wireless medium management would lead to an overall higher wireless system capacity.

  4. SIMULADOR INTERACTIVO DE REDES INALÁMBRICAS BASADAS EN IEEE802.11a

    Directory of Open Access Journals (Sweden)

    Arturo Infante Riello

    2010-09-01

    Full Text Available Normal 0 21 false false false ES-TRAD X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Este artículo presenta los fundamentos y características básicas del diseño de un simulador de redes inalámbricas basadas en el estándar IEEE802.11a, mostrando aspectos de la capa física, canal de radio, programación e interfaz de usuario.

  5. Smart City Pilot Projects Using LoRa and IEEE802.15.4 Technologies

    Directory of Open Access Journals (Sweden)

    Gianni Pasolini

    2018-04-01

    Full Text Available Information and Communication Technologies (ICTs, through wireless communications and the Internet of Things (IoT paradigm, are the enabling keys for transforming traditional cities into smart cities, since they provide the core infrastructure behind public utilities and services. However, to be effective, IoT-based services could require different technologies and network topologies, even when addressing the same urban scenario. In this paper, we highlight this aspect and present two smart city testbeds developed in Italy. The first one concerns a smart infrastructure for public lighting and relies on a heterogeneous network using the IEEE 802.15.4 short-range communication technology, whereas the second one addresses smart-building applications and is based on the LoRa low-rate, long-range communication technology. The smart lighting scenario is discussed providing the technical details and the economic benefits of a large-scale (around 3000 light poles flexible and modular implementation of a public lighting infrastructure, while the smart-building testbed is investigated, through measurement campaigns and simulations, assessing the coverage and the performance of the LoRa technology in a real urban scenario. Results show that a proper parameter setting is needed to cover large urban areas while maintaining the airtime sufficiently low to keep packet losses at satisfactory levels.

  6. Signaling-Free Max-Min Airtime Fairness in IEEE 802.11 Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Youngsoo Lee

    2016-01-01

    Full Text Available We propose a novel media access control (MAC protocol, referred to as signaling-free max-min airtime fair (SMAF MAC, to improve fairness and channel utilization in ad hoc networks based on IEEE 802.11 wireless local area networks (WLANs. We introduce busy time ratio (BTR as a measure for max-min airtime fairness. Each node estimates its BTR and adjusts the transmission duration by means of frame aggregation and fragmentation, so that it can implicitly announce the BTR to neighbor nodes. Based on the announced BTR, each of the neighbor nodes controls its contention window. In this way, the SMAF MAC works in a distributed manner without the need to know the max-min fair share of airtime, and it does not require exchanging explicit control messages among nodes to attain fairness. Moreover, we successfully incorporate the hidden node detection and resolution mechanisms into the SMAF MAC to deal with the hidden node problem in ad hoc networks. The simulation results confirm that the SMAF MAC enhances airtime fairness without degrading channel utilization, and it effectively resolves several serious problems in ad hoc networks such as the starvation, performance anomaly, and hidden node problems.

  7. Achievable Throughput-Based MAC Layer Handoff in IEEE 802.11 Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Wu Haitao

    2009-01-01

    Full Text Available We propose a MAC layer handoff mechanism for IEEE 802.11 Wireless Local Area Networks (WLAN to give benefit to bandwidth-greedy applications at STAs. The proposed mechanism determines an optimal AP with the maximum achievable throughput rather than the best signal condition by estimating the AP's bandwidth with a new on-the-fly measurement method, Transient Frame Capture (TFC, and predicting the actual throughput could be achieved at STAs. Since the TFC is employed based on the promiscuous mode of WLAN NIC, STAs can avoid the service degradation through the current associated AP. In addition, the proposed mechanism is a client-only solution which does not require any modification of network protocol on APs. To evaluate the performance of the proposed mechanism, we develop an analytic model to estimate reliable and accurate bandwidth of the AP and demonstrate through testbed measurement with various experimental study methods. We also validate the fairness of the proposed mechanism through simulation studies.

  8. BER IMPROVEMENT OF WIRELESS LAN IEEE 802.11 STANDARD USING WAVELET PACKET TRANSFORMS

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    2012-09-01

    Full Text Available High data rates and spectral efficiency is the main requirements for wireless communication systems. Orthogonal Frequency Division Multiplexing (OFDM is a special form of multi carrier transmission used to achieve high data rates of the various WLAN standards. WLAN uses an Inverse Fast Fourier Transform (IFFT at the transmitter to modulate a high bit-rate signal onto a number of carriers and ensure orthogonality between the carriers. The FFT-OFDM has a disadvantage that it is inherently inflexible and requires a complex IFFT core. Recently, Wavelet Packet Transform is proposed as an alternate to FFT. It is a multiplexing method in which data is assigned to wavelet sub bands having different time and frequency resolutions. This paper presents a BER analysis of Fourier-based OFDM (FFT-OFDM and Wavelet Packet based OFDM (WPT-OFDM in WLAN standard (IEEE 802.11a. The performance of FFT and WPT OFDM for various modulation techniques such as PSK, DPSK and QAM for varying values of M was evaluated in AWGN Channel.

  9. On the Feasibility of Wireless Multimedia Sensor Networks over IEEE 802.15.5 Mesh Topologies

    Directory of Open Access Journals (Sweden)

    Antonio-Javier Garcia-Sanchez

    2016-05-01

    Full Text Available Wireless Multimedia Sensor Networks (WMSNs are a special type of Wireless Sensor Network (WSN where large amounts of multimedia data are transmitted over networks composed of low power devices. Hierarchical routing protocols typically used in WSNs for multi-path communication tend to overload nodes located within radio communication range of the data collection unit or data sink. The battery life of these nodes is therefore reduced considerably, requiring frequent battery replacement work to extend the operational life of the WSN system. In a wireless sensor network with mesh topology, any node may act as a forwarder node, thereby enabling multiple routing paths toward any other node or collection unit. In addition, mesh topologies have proven advantages, such as data transmission reliability, network robustness against node failures, and potential reduction in energy consumption. This work studies the feasibility of implementing WMSNs in mesh topologies and their limitations by means of exhaustive computer simulation experiments. To this end, a module developed for the Synchronous Energy Saving (SES mode of the IEEE 802.15.5 mesh standard has been integrated with multimedia tools to thoroughly test video sequences encoded using H.264 in mesh networks.

  10. Cross-layer TCP Performance Analysis in IEEE 802.11 Vehicular Environments

    Directory of Open Access Journals (Sweden)

    T. Janevski

    2014-06-01

    Full Text Available In this paper we provide a performance analysis of TCP in IEEE 802.11 vehicular environments for different well-known TCP versions, such as Tahoe, Reno, New Reno, Vegas, and Sack. The parameters of interest from the TCP side are the number of Duplicate Acknowledgements - DupAck, and the number of Delayed Acknowledgements - DelAck, while on the wireless network side the analyzed parameter is the interface queue - IFQ. We have made the analysis for the worst-case distance scenario for single-hop and worst-case multihop vehicular environments. The results show that the number of wireless hops in vehicular environments significantly reduces the TCP throughput. The best average performances considering all scenarios were obtained for TCP Vegas. However, the results show that the interface queue at wireless nodes should be at least five packets or more. On the other side, due to shorter distances in the vehicular wireless network, results show possible flexibility of using different values for the DupAck without degradation of the TCP throughput. On the other side, the introduction of the DelAck parameter provides enhancement in the average TCP throughput for all TCP versions.

  11. A IEEE 802.11e HCCA Scheduler with a Reclaiming Mechanism for Multimedia Applications

    Directory of Open Access Journals (Sweden)

    Anna Lina Ruscelli

    2014-01-01

    Full Text Available The QoS offered by the IEEE 802.11e reference scheduler is satisfactory in the case of Constant Bit Rate traffic streams, but not yet in the case of Variable Bit Rate traffic streams, whose variations stress its scheduling behavior. Despite the numerous proposed alternative schedulers with QoS, multimedia applications are looking for refined methods suitable to ensure service differentiation and dynamic update of protocol parameters. In this paper a scheduling algorithm, Unused Time Shifting Scheduler (UTSS, is deeply analyzed. It is designed to cooperate with a HCCA centralized real-time scheduler through the integration of a bandwidth reclaiming scheme, suitable to recover nonexhausted transmission time and assign that to the next polled stations. UTSS dynamically computes with an O(1 complexity transmission time providing an instantaneous resource overprovisioning. The theoretical analysis and the simulation results highlight that this injection of resources does not affect the admission control nor the centralized scheduler but is suitable to improve the performance of the centralized scheduler in terms of mean access delay, transmission queues length, bursts of traffic management, and packets drop rate. These positive effects are more relevant for highly variable bit rate traffic.

  12. Doença de Alzheimer e espectroscopia por ressonância magnética do hipocampo

    Directory of Open Access Journals (Sweden)

    Engelhardt Eliasz

    2001-01-01

    Full Text Available OBJETIVOS: Obtenção de dados do espectro de metabolitos por ressonância magnética da formação hipocampal no idoso normal e com doença de Alzheimer (DA. MÉTODO: Os indivíduos foram pareados por idade, sendo 20 na amostra normal, CDR=0 e 40 com DA 3 CDR=1 e 2. Utilizou-se aparelho Signa Horizon LX-GE, 1.5T, ¹H-ERM com aplicativo automatizado PROBE/SV, VOI: hc (direito e esquerdo; voxel único (2x2x2cm; TR 1500ms/TE 50ms; PRESS; metabolitos: N-acetilaspartato (Naa, colina (Cho, creatina (Cr, mio-inositol (mI. RESULTADOS: Os presentes dados se referem aos quocientes de Naa, Cho e mI, com Cr tomada como referência e relação mI/Naa. O estudo mostrou o Naa reduzido, o mI e a relação mI/Naa aumentados e os resultados em relação à Cho foram variados. Os resultados da amostra global dos pacientes com DA em comparação à média ± dp da amostra normal foram significativos para Naa, mI e mI/Naa (p<0,01. A precisão, tomando os valores de modo individual das duas amostras, mostrou sensibilidade, especificidade e valor preditivo positivo satisfatórios. CONCLUSÃO: Os presentes resultados podem ser usados como ferramenta útil para detectar alterações patológicas no hipocampo de pacientes com DA, permitindo diagnóstico de maior precisão e mais precoce da doença.

  13. Real-Time Support on IEEE 802.11 Wireless Ad-Hoc Networks: Reality vs. Theory

    Science.gov (United States)

    Kang, Mikyung; Kang, Dong-In; Suh, Jinwoo

    The usable throughput of an IEEE 802.11 system for an application is much less than the raw bandwidth. Although 802.11b has a theoretical maximum of 11Mbps, more than half of the bandwidth is consumed by overhead leaving at most 5Mbps of usable bandwidth. Considering this characteristic, this paper proposes and analyzes a real-time distributed scheduling scheme based on the existing IEEE 802.11 wireless ad-hoc networks, using USC/ISI's Power Aware Sensing Tracking and Analysis (PASTA) hardware platform. We compared the distributed real-time scheduling scheme with the real-time polling scheme to meet deadline, and compared a measured real bandwidth with a theoretical result. The theoretical and experimental results show that the distributed scheduling scheme can guarantee real-time traffic and enhances the performance up to 74% compared with polling scheme.

  14. Diseño y verificación de un amplificador para IEEE802.16

    OpenAIRE

    Lloret Arjona, Patricia

    2005-01-01

    Hace más de 6 años se empezó a gestar el IEEE802.16, un estándar para una nueva tecnología inalámbrica de banda ancha. El primer capítulo consiste en una introducción sobre este estándar, su evolución, las diferentes versiones que han ido apareciendo y las características principales de cada una de ellas, seguido de un pequeño comentario sobre su faceta comercial, WiMAX. El IEEE802.16 está empezando a tener relevancia, de modo que se decidió realizar un amplificador capaz de...

  15. Design and implementation of an IEEE 802.11 baseband OFDM transceiver in 0.18 μm CMOS

    International Nuclear Information System (INIS)

    Wu Bin; Zhou Yumei; Zhu Yongxu; Zhang Zhengdong; Cai Jingjing

    2011-01-01

    An SISO IEEE 802.11 baseband OFDM transceiver ASIC is implemented. The chip can support all of the SISO IEEE 802.11 work modes by optimizing the key module and sharing the module between the transmitter and receiver. The area and power are decreased greatly compared with other designs. The baseband prototype has been verified under the WLAN baseband test equipment and through transferring the video. The 0.18 μm 1P/6M CMOS technology layout is finished and the chip is fabricated in SMIC, which occupies a 2.6 x 2.6 mm 2 area and consumes 83 mW under typical work modes. (semiconductor integrated circuits)

  16. The Performance Evaluation of an IEEE 802.11 Network Containing Misbehavior Nodes under Different Backoff Algorithms

    Directory of Open Access Journals (Sweden)

    Trong-Minh Hoang

    2017-01-01

    Full Text Available Security of any wireless network is always an important issue due to its serious impacts on network performance. Practically, the IEEE 802.11 medium access control can be violated by several native or smart attacks that result in downgrading network performance. In recent years, there are several studies using analytical model to analyze medium access control (MAC layer misbehavior issue to explore this problem but they have focused on binary exponential backoff only. Moreover, a practical condition such as the freezing backoff issue is not included in the previous models. Hence, this paper presents a novel analytical model of the IEEE 802.11 MAC to thoroughly understand impacts of misbehaving node on network throughput and delay parameters. Particularly, the model can express detailed backoff algorithms so that the evaluation of the network performance under some typical attacks through numerical simulation results would be easy.

  17. Design and implementation of an IEEE 802.11 baseband OFDM transceiver in 0.18 μm CMOS

    Science.gov (United States)

    Bin, Wu; Yumei, Zhou; Yongxu, Zhu; Zhengdong, Zhang; Jingjing, Cai

    2011-05-01

    An SISO IEEE 802.11 baseband OFDM transceiver ASIC is implemented. The chip can support all of the SISO IEEE 802.11 work modes by optimizing the key module and sharing the module between the transmitter and receiver. The area and power are decreased greatly compared with other designs. The baseband prototype has been verified under the WLAN baseband test equipment and through transferring the video. The 0.18 μm 1P/6M CMOS technology layout is finished and the chip is fabricated in SMIC, which occupies a 2.6 × 2.6 mm2 area and consumes 83 mW under typical work modes.

  18. Design and implementation of an IEEE 802.11 baseband OFDM transceiver in 0.18 {mu}m CMOS

    Energy Technology Data Exchange (ETDEWEB)

    Wu Bin; Zhou Yumei; Zhu Yongxu; Zhang Zhengdong; Cai Jingjing, E-mail: wubin@ime.ac.cn [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

    2011-05-15

    An SISO IEEE 802.11 baseband OFDM transceiver ASIC is implemented. The chip can support all of the SISO IEEE 802.11 work modes by optimizing the key module and sharing the module between the transmitter and receiver. The area and power are decreased greatly compared with other designs. The baseband prototype has been verified under the WLAN baseband test equipment and through transferring the video. The 0.18 {mu}m 1P/6M CMOS technology layout is finished and the chip is fabricated in SMIC, which occupies a 2.6 x 2.6 mm{sup 2} area and consumes 83 mW under typical work modes. (semiconductor integrated circuits)

  19. IEEE standard requirements for reliability analysis in the design and operation of safety systems for nuclear power generating stations

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The purpose of this standard is to provide uniform, minimum acceptable requirements for the performance of reliability analyses for safety-related systems found in nuclear-power generating stations, but not to define the need for an analysis. The need for reliability analysis has been identified in other standards which expand the requirements of regulations (e.g., IEEE Std 379-1972 (ANSI N41.2-1972), ''Guide for the Application of the Single-Failure Criterion to Nuclear Power Generating Station Protection System,'' which describes the application of the single-failure criterion). IEEE Std 352-1975, ''Guide for General Principles of Reliability Analysis of Nuclear Power Generating Station Protection Systems,'' provides guidance in the application and use of reliability techniques referred to in this standard

  20. Error detecting capabilities of the shortened Hamming codes adopted for error detection in IEEE Standard 802.3

    Science.gov (United States)

    Fujiwara, Toru; Kasami, Tadao; Lin, Shu

    1989-09-01

    The error-detecting capabilities of the shortened Hamming codes adopted for error detection in IEEE Standard 802.3 are investigated. These codes are also used for error detection in the data link layer of the Ethernet, a local area network. The weight distributions for various code lengths are calculated to obtain the probability of undetectable error and that of detectable error for a binary symmetric channel with bit-error rate between 0.00001 and 1/2.

  1. Comparison and Analysis of IEEE 344 and IEC 60980 standards for harmonization of seismic qualification of safety-related equipment

    International Nuclear Information System (INIS)

    Lee, Young Ok; Kim, Jong Seog; Seo, Jeong Ho; Kim, Myung Jun

    2011-01-01

    The seismic qualification of safety related equipment in nuclear power plants should demonstrate an equipment's ability to perform its safety function during/or after the time it is subjected to the forces resulting from one SSE. In addition, the equipment must withstand the effects of a number of OBEs, preceding the SSE. IEEE 344 and IEC 60980 present the criteria for establishing procedures demonstrating that the Class 1E equipment can meet its performance requirement during seismic events. Currently, IEEE 344 is used for regulation of nuclear power plant in the United State whereas IEC 60980 is mainly used in Europe. In particular, NPPs of France and China apply with RCC-E and GB that are domestic standards, respectively. Equipment supplier and Utility have difficulties because of different applicable standards. Equipment supplier to export S/R components/equipment to other standard area performs additional seismic qualification. For example, equipment are qualifies according to IEC 60980, RCC-E, GB although they have been qualified in accordance with IEEE 344. Also, utility to attempt power up-rate, life extension of NPP constructed under rules of RCC-E such as Ulchin NPP 1 and 2 has similar difficulties. RCC-E endorses IEC 60980 and GB is almost same as IEC 60980 except minor difference of earthquake environment definition. Therefore this paper surveys the similarities and differences between IEEE 344 and IEC 60980. In addition, this paper considers how the two sets of standards may be used in a complementary fashion to be possible using one or the other standard area

  2. Introduction to the special issue on the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum.

    Science.gov (United States)

    Burt, Eric; Gill, Patrick

    2012-03-01

    The 8 invited and 17 contributed papers in this special issue focus on the following topical areas covered at the 2011 Joint IEEE International Frequency Control Symposium and European Frequency and Time Forum, held in San Francisco, California: 1) Materials and Resonators; 2) Oscillators, Synthesizers, and Noise; 3) Microwave Frequency Standards; 4) Sensors and Transducers; 5) Timekeeping and Time and Frequency Transfer; and 6) Optical Frequency Standards.

  3. Dynamic subframe allocation for mobile broadband m-health using IEEE 802.16j mobile multihop relay networks.

    Science.gov (United States)

    Alinejad, Ali; Istepanian, R S H; Philip, N

    2012-01-01

    The concept of 4G health will be one of the key focus areas of future m-health research and enterprise activities in the coming years. WiMAX technology is one of the constituent 4G wireless technologies that provides broadband wireless access (BWA). Despite the fact that WiMAX is able to provide a high data rate in a relatively large coverage; this technology has specific limitations such as: coverage, signal attenuation problems due to shadowing or path loss, and limited available spectrum. The IEEE 802.16j mobile multihop relay (MMR) technology is a pragmatic solution designed to overcome these limitations. The aim of IEEE 802.16j MMR is to expand the IEEE 802.16e's capabilities with multihop features. In particular, the uplink (UL) and downlink (DL) subframe allocation in WiMAX network is usually fixed. However, dynamic frame allocation is a useful mechanism to optimize uplink and downlink subframe size dynamically based on the traffic conditions through real-time traffic monitoring. This particular mechanism is important for future WiMAX based m-health applications as it allows the tradeoff in both UL and DL channels. In this paper, we address the dynamic frame allocation issue in IEEE 802.16j MMR network for m-health applications. A comparative performance analysis of the proposed approach is validated using the OPNET Modeler(®). The simulation results have shown an improved performance of resource allocation and end-to-end delay performance for typical medical video streaming application.

  4. Mathematical Analysis of EDCA's Performance on the Control Channel of an IEEE 802.11p WAVE Vehicular Network

    Directory of Open Access Journals (Sweden)

    Hussein T. Mouftah

    2010-01-01

    Full Text Available Wireless networks for vehicular environments are gaining increasing importance due to their ability to provide a means for stations on the roadside and radio units on board of vehicles to communicate and share safety-related information, thus reducing the probability of accidents and increasing the efficiency of the transportation system. With this goal in mind, the IEEE is currently developing the Wireless Access in Vehicular Environments (WAVE IEEE 802.11p standard. WAVE devices use the IEEE 802.11's Enhanced Distributed Channel Access (EDCA MAC protocol to compete for the transmission medium. This work proposes an analytical tool to evaluate the performance of EDCA under the specific conditions of the so-called control channel (CCH of a WAVE environment, including the particular EDCA parameter values and the fact that all safety-critical data frames are broadcasted. The protocol is modeled using Markov chains and results related to throughput, frame-error rate, buffer occupancy and delay are obtained under different traffic-load conditions. The main analysis is performed assuming that the CCH works continuously, and then an explanation is given as to the considerations that are needed to account for the fact that activity on the CCH is intermittent.

  5. Performance Analysis of IEEE 802.15.6 CSMA/CA Protocol for WBAN Medical Scenario through DTMC Model.

    Science.gov (United States)

    Kumar, Vivek; Gupta, Bharat

    2016-12-01

    The newly drafted IEEE 802.15.6 standard for Wireless Body Area Networks (WBAN) has been concentrating on a numerous medical and non-medical applications. Such short range wireless communication standard offers ultra-low power consumption with variable data rates from few Kbps to Mbps in, on or around the proximity of the human body. In this paper, the performance analysis of carrier sense multiple access with collision avoidance (CSMA/CA) scheme based on IEEE 802.15.6 standard in terms of throughput, reliability, clear channel assessment (CCA) failure probability, packet drop probability, and end-to-end delay has been presented. We have developed a discrete-time Markov chain (DTMC) to significantly evaluate the performances of IEEE 802.15.6 CSMA/CA under non-ideal channel condition having saturated traffic condition including node wait time and service time. We also visualize that, as soon as the payload length increases the CCA failure probability increases, which results in lower node's reliability. Also, we have calculated the end-to-end delay in order to prioritize the node wait time cause by backoff and retransmission. The user priority (UP) wise DTMC analysis has been performed to show the importance of the standard especially for medical scenario.

  6. IEEE 845 - a proposed guideline for use of human factors in design and retrofit design of nuclear power plants

    International Nuclear Information System (INIS)

    Schurman, D.L.

    1987-01-01

    This paper describes the development and content of the Institute of Electrical and Electronics Engineers (IEEE) Standard 845. This guide was developed by Working Group 7.2 of Subcommittee 7 of the Nuclear Power Engineering Committee of the Power Engineering Society of the IEEE. The guide has been approved by the Nuclear Power Engineering Committee (NPEC) and is now in the standards development and approval process. The guide is the first standards action approved by the NPEC of IEEE and is presented here to obtain wider peer response to its content. The guide provides a systematic framework for selection of human factors techniques and for the use of those techniques. The guide also provides a list of commonly used human factors techniques, along with a commentary about cost, ease of use, and other characteristics of each of the techniques. The guide is written with the project engineer and design engineer in mind. Thus, the guide attempts to provide a basis for the systematic selection of human factors techniques for various purposes and guidance regarding which of these techniques is likely to require the assistance of a human factors expert to apply

  7. Service differentiated and adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems.

    Science.gov (United States)

    Xia, Feng; Li, Jie; Hao, Ruonan; Kong, Xiangjie; Gao, Ruixia

    2013-01-01

    Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay.

  8. Structural modification of trans-cinnamic acid using Colletotrichum acutatum

    OpenAIRE

    Rodrigo Velasco B.; Jesús H. Gil G.; Carlos M. García P.; Diego L. Durango R.

    2012-01-01

    Se estudió la biotransformación de ácido trans-cinámico mediante células completas del hongo fitopatógeno nativo colombiano Colletotrichum acutatum. Inicialmente, se evaluó la fungitoxicidad de este compuesto contraC. acutatum; el ácido trans-cinámico exhibió una toxicidad moderada a débil contra el microorganismo y aparentemente se presentó un mecanismo de detoxificación. Luego, para estudiar tal mecanismo y explorar la capacidad de este hongo para biotransformar el ácido trans-cinámico en ...

  9. Cours de magnétisme en sept leçons augmenté du rapport sur les expériences magnétiques faites par la commission de l'Académie Royale de Médecine en 1831

    CERN Document Server

    du Potet, Baron

    2015-01-01

    Extrait : ""Pénétré des bienfaits qui doivent résulter pour le genre humain de la découverte du magnétisme animal, je me suis décidé à venir vous en entretenir. Ce n'est pas sans quelque crainte toutefois, car les phénomènes magnétiques que j'ai à vous faire connaître sont si étonnants qu'ils pourront souvent vous paraître exagérés : mais plus ils vous paraîtront extraordinaires et plus ils mériteront de fixer votre attention, s'ils sont vrais.""

  10. Metais pesados no solo e mamoneira adubada com biossólido e silicato de cálcio e magnésio

    Directory of Open Access Journals (Sweden)

    Altina L. Nascimento

    2015-05-01

    Full Text Available O biossólido é excelente fonte de nutrientes de plantas; entretanto, pode contaminar o solo. O trabalho teve por objetivo avaliar a influência da adubação com composto de lodo de esgoto e silicato de cálcio e magnésio, nos teores de metais pesados no solo e em plantas de mamona. O experimento foi conduzido no Instituto de Ciências Agrárias da UFMG em Montes Claros, MG, no período de junho a dezembro de 2010. O cultivo foi realizado em área de Cambissolo Háplico utilizando-se a mamona (Ricinus communis L. variedade BRS Energia. O delineamento foi em blocos casualizados em arranjo fatorial 2 x 4, com 3 repetições, sendo 2 doses de silicato de cálcio e magnésio (0 e 1 t ha-1 e 4 doses de composto de lodo de esgoto (0; 23,81; 47,62 e 71,43 t ha-1, em base seca. Não houve interação entre as doses de silicato de cálcio e composto de lodo de esgoto, bem como o silicato de cálcio e magnésio não influenciou os teores de metais pesados no solo e na planta. No solo os teores de Zn e Cu aumentaram com o incremento das doses de composto de lodo de esgoto sendo que Ni, Pb, Cd e Cr não foram influenciados pela aplicação deste resíduo. Na planta com aumento das doses de composto de lodo de esgoto houve aumento apenas nos teores de Cd e Pb.

  11. Paralelismo clínico e imagenológico por resonancia magnética de los procesos inflamatorios de la médula espinal

    Directory of Open Access Journals (Sweden)

    Rómel Sarmiento Ducóngers

    2017-05-01

    Full Text Available Con el objetivo de identificar las características clínicas y por resonancia magnética de las lesiones inflamatorias de la médula espinal, se realizó un estudio observacional descriptivo transversal, de 56 pacientes, atendidos en los hospitales provinciales de Santiago de Cuba “Dr. Juan Bruno Zayas Alfonso” y “Dr. Saturnino Lora”, durante el periodo comprendido entre enero de 2014 hasta junio de 2015. Las características clínicas de las lesiones inflamatorias de la médula espinal fueron la cuarta década de la vida y el sexo masculino (60,7%, con síntomas predominantes como el dolor, la paresia y la parestesia. Existió predominio de las mielitis compresiva e inflamatoria. Al explorar el grado de concordancia entre la clínica y el informe de la resonancia magnética se obtuvo un índice de Kappa de 0,35. El diagnóstico imagenológico más relevante fue la mielitis compresiva en correspondencia con el diagnóstico clínico, no obstante la investigación permitió determinar que la concordancia entre la clínica y el diagnóstico imagenológico por resonancia magnética en los estudios realizados a estos pacientes en el periodo de estudio fue débil.

  12. Zonación de la contaminación por metales pesados en la cuenca del Almendares según mapeo de la susceptibilidad magnética

    Directory of Open Access Journals (Sweden)

    Ida Inés Pedroso-Herrera

    2013-09-01

    Full Text Available La susceptibilidad magnética de los suelos de la cuenca del río Almendares se tomó como indicador preliminar de la contaminación potencial por metales pesados. Para obtener el esquema de zonación de la contaminación se realizaron mediciones de la susceptibilidad magnética en polígonos y perfiles de áreas potencialmente contaminadas. Se realizó un levantamiento kappamétrico a escala 1: 200 000, usando una red de 2x2 km, y se elaboraron estadísticamente datos de susceptibilidad magnética en suelos contaminados y en los no contaminados por metales pesados. Con base en la nueva versión de la Clasificación Genética de los Suelos de Cuba, los resultados de la elaboración estadística de los datos de susceptibilidad magnética y las concentraciones de metales pesados en muestras de suelo, se establecieron los rangos de susceptibilidad magnética que caracterizan los suelos contaminados en los grupos genéticos presentes en la cuenca. Como resultado se obtuvo el mapa de zonación de la contaminación por metales pesados de la cuenca del río Almendares

  13. Magnētisku dipolu rotācijas inducēta šķidra metāla kustības eksperimentāla izpēte

    OpenAIRE

    Beinerts, Toms

    2009-01-01

    Darba mērķis ir eksperimentāli izpētīt inducēto šķidrā metāla kustību no rotējošiem cilindriskiem magnētiem, kuru magnetizācija vērta ortogonāli asij. Darbā tiek izpētīta pasaulē vel nekur nerealizēta magnētiskā sistēma, ar mērķi noskaidrot vai šādus magnētus var lietot efektīvai šķidro metālu maisīšanai. Tika izveidota eksperimentā ierīce, kas ļāva nomērīt inducētās šķidrā metālā kustības ātrumu atkarībā no magnētu rotācijas frekvences un attāluma starp magnētiem un šķidrā metāla rezervuāru....

  14. Ionising radiation and trans-generational instability

    International Nuclear Information System (INIS)

    Vrhovac, I.; Niksic, G.

    2007-01-01

    Indirect monitoring of the impact posed by ionising radiation to the genome instability of the descendants, consequent to the irradiation of one of their parents, boils down to the investigation of changes occurring exclusively in the mini-satellite loci of the cells constituting the gametal developmental line. The resultant mini-satellite mutations are expressed in their percentages, and equal to the ratio of the number of mutated alleles in that particular generation over the total number of alleles present. The impact of ionising radiation to the irradiated parent's offspring was first noticed on haematopoietic mouse stem-cells. Even though an irradiated cell of a female parent lacks any mutations whatsoever, daughter cells present with the increased mutation rates. The observed phenomenon of the so called trans-generational instability has been defined as the occurrence of mutations in the genome of individuals originating from the irradiated ancestors. Due to the aforementioned, one can conclude that these mutations need not be present in the irradiated parental cells, and do not necessarily vanish in the next few generations, but may result in the increase in mutation rates observed in the latter. The results of the investigations performed on the animal model, as well as of those carried out in human population, point to the occurrence of significant changes to be found on mini-satellite loci of the descending generation, while the mechanism underlying those changes hasn't been completely clarified yet, and, therefore, calls for the further investigation. (author)

  15. Optimizing the MAC Protocol in Localization Systems Based on IEEE 802.15.4 Networks

    Directory of Open Access Journals (Sweden)

    Juan J. Pérez-Solano

    2017-07-01

    Full Text Available Radio frequency signals are commonly used in the development of indoor localization systems. The infrastructure of these systems includes some beacons placed at known positions that exchange radio packets with users to be located. When the system is implemented using wireless sensor networks, the wireless transceivers integrated in the network motes are usually based on the IEEE 802.15.4 standard. But, the CSMA-CA, which is the basis for the medium access protocols in this category of communication systems, is not suitable when several users want to exchange bursts of radio packets with the same beacon to acquire the radio signal strength indicator (RSSI values needed in the location process. Therefore, new protocols are necessary to avoid the packet collisions that appear when multiple users try to communicate with the same beacons. On the other hand, the RSSI sampling process should be carried out very quickly because some systems cannot tolerate a large delay in the location process. This is even more important when the RSSI sampling process includes measures with different signal power levels or frequency channels. The principal objective of this work is to speed up the RSSI sampling process in indoor localization systems. To achieve this objective, the main contribution is the proposal of a new MAC protocol that eliminates the medium access contention periods and decreases the number of packet collisions to accelerate the RSSI collection process. Moreover, the protocol increases the overall network throughput taking advantage of the frequency channel diversity. The presented results show the suitability of this protocol for reducing the RSSI gathering delay and increasing the network throughput in simulated and real environments.

  16. Optimizing the MAC Protocol in Localization Systems Based on IEEE 802.15.4 Networks.

    Science.gov (United States)

    Pérez-Solano, Juan J; Claver, Jose M; Ezpeleta, Santiago

    2017-07-06

    Radio frequency signals are commonly used in the development of indoor localization systems. The infrastructure of these systems includes some beacons placed at known positions that exchange radio packets with users to be located. When the system is implemented using wireless sensor networks, the wireless transceivers integrated in the network motes are usually based on the IEEE 802.15.4 standard. But, the CSMA-CA, which is the basis for the medium access protocols in this category of communication systems, is not suitable when several users want to exchange bursts of radio packets with the same beacon to acquire the radio signal strength indicator (RSSI) values needed in the location process. Therefore, new protocols are necessary to avoid the packet collisions that appear when multiple users try to communicate with the same beacons. On the other hand, the RSSI sampling process should be carried out very quickly because some systems cannot tolerate a large delay in the location process. This is even more important when the RSSI sampling process includes measures with different signal power levels or frequency channels. The principal objective of this work is to speed up the RSSI sampling process in indoor localization systems. To achieve this objective, the main contribution is the proposal of a new MAC protocol that eliminates the medium access contention periods and decreases the number of packet collisions to accelerate the RSSI collection process. Moreover, the protocol increases the overall network throughput taking advantage of the frequency channel diversity. The presented results show the suitability of this protocol for reducing the RSSI gathering delay and increasing the network throughput in simulated and real environments.

  17. Crystallinity and the effect of ionizing radiation in polyethylene. V. Distribution of trans-vinylene and trans, trans conjugated double bonds in linear polyethylene

    International Nuclear Information System (INIS)

    Patel, G.N.

    1975-01-01

    Freeze-dried chain folded single crystals and the single crystals without amorphous surface layers (crystalline cores) of different thicknesses of linear polyethylene were irradiated with 60 Co γ-rays up to 600 Mrad. Concentration of trans-vinylene double bonds and conjugated diene produced during irradiation of the crystals was measured by infrared. Concentrations of trans-vinylene and of the conjugated diene were independent of thickness of crystalline core which suggest that the double bonds were randomly distributed in the crystalline parts of the crystals. Concentrations of trans-vinylene and of conjugated double bonds were lower in chain-folded crystals than in the crystalline cores and this suggests that the folds (amorphous surface layers) are less preferential sites for formation of the double bonds. The zero-order growth and first-order decay kinetics of trans-vinylene double bonds was studied by the equation derived by Dole et al. The equation is strictly obeyed up to 300 Mrad and the results then deviate. Since there is the decay of trans-vinylene double bonds and though there are no crosslinks in the crystalline cores, it has been suggested that the decay of the double bond does not result in the crosslinks

  18. Modelamiento y simulación de la contracción muscular mediante la estimulación magnética externa

    OpenAIRE

    Bermeo Moyano, Juan Pablo; Sánchez Sánchez, Carlos Felipe

    2017-01-01

    El proyecto inicia revisando las ecuaciones de Maxwell, para simular y estimar las corrientes inducidas en un tejido muscular por un campo magnético mediante el MEF: M. Elementos Finitos. Se simula la fuerza muscular con el modelo de seis parámetros y optimizado por algoritmos genéticos para ajustar el modelo teórico con las medidas experimentales. The present project begins with the revision of the Maxwell equations, to simulate and estimate the currents induced in a muscle tissue by a ma...

  19. Efecto inmunomodulador de la solución CM-95 tratada magnéticamente en ratones Balb/c inoculados con 5-fluorouracilo

    Directory of Open Access Journals (Sweden)

    Clara Martínez

    2011-04-01

    Full Text Available El 5-fluorouracilo es un antineoplásico usado en la terapia del cáncer y posee acción inmunosupresora al inhibir la proliferación de células del tejido hematopoyético. En este trabajo se evaluó el efecto inmunomodulador de la solución CM-95 tratada magnéticamente en ratones Balb/c inoculados con 5-fluorouracilo a través de su acción protectora rehabilitadora sobre parámetros celulares y tisulares del tejido hematopoyético. A los ratones, entre 20-22 g de peso y 6 semanas de nacidos, se les administró esta solución CM-95 tratada magnéticamente por vía intraperitoneal en un esquema de dos inoculaciones; luego se administró por la misma vía el 5_fluorouracilo a una dosis de 150 mg/m2 de superficie corporal de cada ratón. Se evaluó el conteo total y diferencial de leucocitos antes de inocular el 5-fluorouracilo, y a los tres y siete días de aplicado este. La celularidad de médula ósea y bazo y la observación microscópica del corte histológico de hígado y bazo por la técnica de inclusión en parafina y tinción con eosina hematoxilina al 10% se evaluaron a los siete días de haber aplicado el 5- fluorouracilo. La solución CM-95, tratada magnéticamente, logró modular los efectos del 5-fluorouracilo con una actividad protectora rehabiltadora, para los parámetros evaluados en médula ósea, sangre periférica, bazo e hígado. Estos resultados abren nuevas perspectivas para la aplicación del sistema acuoso tratado magnéticamente como inmunomodulador.

  20. Desarrollo de un sistema de suspensión magnética para la determinación de densidad de líquidos

    OpenAIRE

    Centeno González, Luz María; Castillo Castañeda, Eduardo; Becerra Santiago, Luis Omar; Rochín García, Alberto

    2013-01-01

    La densidad es una magnitud derivada de las magnitudes de base masa y longitud, está definida como masa por unidad de volumen y su unidad en el Sistema Internacional de Unidades (SI) es el kg/m3. En las últimas cinco décadas, en el ámbito de la metrología primaria, se han desarrollado sistemas de suspensión magnética para la determinación de densidad de fluidos, lo que ha permitido realizar investigaciones sobre las características físicas de líquidos y gases. El presente trabajo tiene como o...