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Vangelis Gazis Nancy Alonistioti Nikos Houssos Maria Koutsopoulou Stefan Gessler Juergen Quittek 《Journal of Network and Systems Management》2006,14(2):221-241
Mobile communications beyond 3G will integrate different (but complementary) access technologies into a common platform to deliver value-added services and multimedia content in an optimum way. However, the numerous possible configurations of mobile networks complicated the dynamic deployment of mobile applications. Therefore, research is intensely seeking a service provisioning framework that is technology-independent, supports multiple wireless network technologies, and can interwork high-level service management tasks to network management operations. This paper presents an open value chain paradigm, a model for downloadable applications and a mediating platform for service provisioning in beyond 3G mobile settings. Furthermore, we introduce mechanisms that support a coupled interaction between service deployment and network configuration operations, focusing on the dynamic provisioning of QoS state to data path devices according to the requirements of dynamically downloadable mobile value-added services (VAS).
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Vangelis GazisEmail: |
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Joseph Ramsey Paul Gazis Ted Roush Peter Spirtes Clark Glymour 《Data mining and knowledge discovery》2002,6(3):277-293
Reflectance spectroscopy is a standard tool for studying the mineral composition of rock and soil samples and for remote sensing of terrestrial and extraterrestrial surfaces. We describe research on automated methods of mineral identification from reflectance spectra and give evidence that a simple algorithm, adapted from a well-known search procedure for Bayes nets, identifies the most frequently occurring classes of carbonates with reliability equal to or greater than that of human experts. We compare the reliability of the procedure to the reliability of several other automated methods adapted to the same purpose. Evidence is given that the procedure can be applied to some other mineral classes as well. Since the procedure is fast with low memory requirements, it is suitable for on-board scientific analysis by orbiters or surface rovers. 相似文献
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Third-generation (3G) and beyond 3G mobile communication systems must provide interoperability with the Internet, increase throughput for mobile devices, and optimize their operation for multimedia applications. The limited ability of traditional layered architectures to exploit the unique nature of wireless communication has fostered the introduction of cross-layer design solutions that allow optimized operation for mobile devices in the modern heterogeneous wireless environment. In this article we present the major cross-layer design solutions that handle such problems, and discuss cross-layer implementations with a focus on functional entities that support cross-layer processes and the respective signaling. In addition, we consider the associated architectural complexity and communication overhead they introduce. Furthermore, we point out the major open technical challenges in the cross-layer design research area. Finally, we conclude our article with a summary of cross-layer approaches developed thus far and provide directions for future work. 相似文献
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Global consensus on the next generation of wireless mobile communications, broadly termed “beyond 3G”, sketches a heterogeneous
infrastructure comprising different wireless systems in a complementary manner and vested with reconfiguration capabilities,
which support a flexible and dynamic adaptation of the wireless network and its spectrum resources to meet the ever-changing
service requirements. For ubiquitous reconfiguration to become a practical capability of mobile communication systems, it
is necessary to establish a global architecture for modeling, expressing, and circulating essential metadata related to reconfiguration,
including reconfigurable device capabilities and semantic properties of protocol stacks. We outline the relevant standardization
initiatives in the mobile domain, summarize existing work in reconfiguration-supporting architectures, and identify key shortcomings
that may hinder the advent of ubiquitously reconfigurable systems. Further on, we point out some major limitations of current
metadata standards in the mobile domain for the representation of capability information pertaining to reconfigurable protocol
stacks. Next, we identify essential metadata classes in support of reconfigurable communication systems, introducing an associated
object-oriented UML model. We elaborate on the design rationale of the UML model, presenting and discussing the alternative
metadata representation standards and suitable encoding formats. Finally, we demonstrate the suitability of our UML model
by applying our reconfiguration-supporting vocabulary in the cases of a standardized protocol stack of 3G mobile devices and
stationary 3G cellular network elements.
Vangelis Gazis received his B.Sc. and M.Sc. (Communication Networking) degrees from the Department of Informatics & Telecommunications of
the University of Athens, Greece, in 1995, and 1998, respectively. He also received an M.B.A. degree from the Athens University
of Economics and Business in 2001. Since 1996 until, he has been with the research staff of the Communication Networks Laboratory
(CNL) of the University of Athens. He has participated in national and European research projects (MOBIVAS, ANWIRE) of the
IST framework programme. He specializes in reconfigurable mobile systems and networks for beyond 3G, metadata and ontology
languages, reflective and component middleware, adaptable services and open API frameworks for telecommunications. He is currently
a Ph.D. candidate in the Department of Informatics & Telecommunications of the University of Athens.
Nancy Alonistioti holds a B.Sc. degree and a Ph.D. degree in informatics and telecommunications from the University of Athens. Presently, she
is a senior researcher in the Department of Informatics and Telecommunications of the University of Athens. In the past, she
has held a research position with the Institute of Informatics and Telecommunications of NCSR “Demokritos” in the areas of
protocol and service design and testing, mobile systems (UMTS), open architectures, and software defined radio systems and
networks. Her current research interests are in reconfigurable mobile systems and networks beyond 3G, and adaptable services,
pervasive computing and context awareness. She has participated in several national and European R&D projects, and has been
the technical manager of the IST-MOBIVAS and IST-ANWIRE projects, which have had a focus on reconfigurable mobile systems,
networks an respective service provision. She is currently a member of the management team and workpackage leader in the FP6
IST-E2R project on reconfigurability; she also serves as technical manager for the University of Athens in the FP6 IST-LIAISON
project, which focuses on location based services in working environments. Dr Alonistioti is co-editor and co-author of the
book entitled “Software defined radio, Architectures, Systems and Functions”, published by John Wiley in May 2003. She has
authored over 55 publications in the area of mobile communications and reconfigurable systems and networks.
Lazaros Merakos received the Diploma in electrical and mechanical engineering from the National Technical University of Athens, Athens, Greece,
in 1978, and the M.S. and Ph.D. degrees in electrical engineering from the State University of New York, Buffalo, in 1981
and 1984, respectively. From 1983 to 1986, he was on the faculty of the Electrical Engineering and Computer Science Department,
University of Connecticut, Storrs. From 1986 to 1994, he was on the faculty of the Electrical and Computer Engineering Department,
Northeastern University, Boston, MA. During the period 1993D1994, he served as Director of the Communications and Digital
Processing Research Center, Northeastern University. During the summers of 1990 and 1991, he was a Visiting Scientist at the
IBM T. J. Watson Research Center, Yorktown Heights, NY. In 1994, he joined the faculty of the University of Athens, Athens,
Greece, where he is presently a Professor in the Department of Informatics and Telecommunications, and Director of the Communication
Networks Laboratory (UoA-CNL) and the Networks Operations and Management Center. Since 1995, he is leading the research activities
of UoA-CNL in the area of mobile communications, in the framework of the Advanced Communication Technologies and Services
(ACTS) and Information Society Technologies (IST) programs funded by the European Union (projects RAINBOW, Magic WAND, WINE,
MOBIVAS, POLOS, ANWIRE, E2R, LIAISON). His research interests are in the design and performance analysis of communication
networks, and wireless/mobile communication systems and services. He has authored more than 190 papers in the above areas.
Dr. Merakos is Chairman of the Board of the Greek Universities Network, the Greek Schools Network, and Member of the Board
of the Greek Research Network. In 1994, he received the Guanella Award for the Best Paper presented at the International Zurich
Seminar on Mobile Communications. 相似文献
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Summary An investigation is given of the lowest symmetric (extensional) and the lowest antisymmetric (flexural) mode of waves in a cubic crystal plate bounded by two planes of symmetry. The investigation was carried out using the continuum theory of anisotropic elasticity, and also using a simple cubic lattice model. Particular attention was given to the change of the character of both the extensional and flexural mode, which takes place as the wave length is decreased from infinity down to values of the order of the plate thickness. Both modes tend to become surface modes whenever surface waves are possible along the direction of propagation. However, some essential differences were observed, regarding this transition from bulk modes to surface modes, between materials which propagateRayleigh surface waves and those which propagate generalizedRayleigh surface waves.
With 4 Figures 相似文献
Zusammenfassung Es werden die niedrigsten Schwingungsformen in einem kubischen Plattenkristall, der von zwei Symmetrieebenen begrenzt wird, untersucht, und zwar sowohl die symmetrische (Dehnungs-) als auch die antisymmetrische (Biegungs-) Schwingung. Die Untersuchung wird mit Hilfe der Kontinuumstheorie anisotroper elastischer Medien sowie unter Verwendung des Modells eines einfachen kubischen Gitters durchgeführt. Besondere Aufmerksamkeit wird der Änderung des Charakters der Dehnungs- und der Biegeschwingung gewidmet, welche bei Verkleinerung der Wellenlänge von sehr großen Werten auf solche von der Größenordnung der Plattendicke auftritt. Beide Wellenarten haben das Bestreben, Oberflächenwellen zu werden, solange das Auftreten von Oberflächenwelles in der Ausbreitungsrichtung möglich ist. Es werden aber einige wesentliche Unterschiede beim Übergang von Körperwellen zu Oberflächenwellen beobachtet, je nachdem, ob es sich um Stoffe handelt, in denenRayleighsche Oberflächenwellen oder solche, in denen verallgemeinerteRayleighsche Oberflächenwellen entstehen.
With 4 Figures 相似文献
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European guidelines recommend annual screening for microalbuminuria in patients with Type 1 (insulin-dependent) diabetes mellitus (IDDM) of greater than 5 years' duration and in those with Type 2 (non-insulin-dependent) diabetes mellitus (NIDDM) from diagnosis. To determine the current provision of screening for microalbuminuria we performed a postal survey of all diabetologists in the United Kingdom. Of 556 questionnaires sent, 326 (59%) were returned (246 adult, 57 paediatric, 3 adolescent clinics) and of these 306 (55%) were suitable for analysis. Screening programmes have been established by 210 (69%) diabetologists: 70 of these in the last 2 years. 46 more plan to screen patients with IDDM within 2 years. 155 (92%) of 169 adult programmes perform annual screening in IDDM, 74% according to European guidelines (39% in NIDDM). Other clinics use age, type of diabetes or criteria such as blood pressure to target screening. An albumin/creatinine ratio (52%) on an early morning urine (56%) or random (29%) urine sample is most commonly requested. Financial constraint was the principal reason given in 32 (33%) of 96 clinics that do not currently screen. Other reasons included implementation of other developments with a higher priority (24%) and doubts about the medical value of screening (46%). Assuming respondents are representative of current UK practice, we conclude that microalbuminuria screening is available to patients in many clinics, but is neither universal nor always performed according to European guidelines. 相似文献
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Wisely D. Aghvami H. Gwyn S.L. Zahariadis T. Manner J. Gazis V. Houssos N. Alonistioti N. 《Wireless Communications, IEEE》2003,10(4):26-35
Advances in network architecture, enhancements in signaling protocols, provisioning of end-to-end QoS, worldwide seamless mobility, and flexible service provision are among the major research challenges toward next-generation wireless networks. The integration and interoperability of all these technologies, along with new truly broadband wireless innovations and intelligent user-oriented services will lead toward the so-called 4G wireless networks. In this article we identify the key issues of an innovative transparent IP radio access system that targets 4G networks. 相似文献
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T. Alexopoulos R. Avramidou M. Dris T.A. Filippas E.N. Gazis E. Katsoufis S. Maltezos P. Savva G. Tsipolitis E. Tzamariudaki 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2006,560(2):633-639
ATLAS (A Toroidal LHC ApparatuS) is a general purpose experiment, which will start its operation at the Large Hadron Collider (LHC) at CERN in 2007. The ATLAS detector is designed to study the products of proton–proton collisions at c.m.s. energies of up to 14 TeV. Three Greek Universities have taken the responsibility to construct 112 BIS-MDT (Barrel Inner Small) chambers using 29 000 drift tubes of 170 cm length and 3 cm diameter that have been quality tested before assembly. This work describes the Quality Assurance and Quality Control (QA_QC) procedures for the drift tubes, followed at the High Energy Physics Laboratory of the National Technical University of Athens, while emphasis is given on the obtained results for the above mentioned number of tubes. 相似文献