266,695 research outputs found
Intersystem soft handover for converged DVB-H and UMTS networks
Get PDFDigital video broadcasting for handhelds (DVB-H) is the standard for broadcasting Internet Protocol (IP) data services to mobile portable devices. To provide interactive services for DVB-H, the Universal Mobile Telecommunications System (UMTS) can be used as a terrestrial interaction channel for the unidirectional DVB-H network. The converged DVB-H and UMTS network can be used to address the congestion problems due to the limited multimedia channel accesses of the UMTS network. In the converged network, intersystem soft handover between DVB-H and UMTS is needed for an optimum radio resource allocation, which reduces network operation cost while providing the required quality of service. This paper deals with the intersystem soft handover between DVB-H and UMTS in such a converged network. The converged network structure is presented. A novel soft handover scheme is proposed and evaluated. After considering the network operation cost, the performance tradeoff between the network quality of service and the network operation cost for the intersystem soft handover in the converged network is modeled using a stochastic tree and analyzed using a numerical simulation. The results show that the proposed algorithm is feasible and has the potential to be used for implementation in the real environment
Breaking New Ground in East Asia Library History
No full textReview of Peter X. Zhou. Collecting Asia: East Asian Libraries in North America (2010).Published in H-Net Reviews in the Humanities and Social Sciences and available at: http://www.h-net.org/reviews/showrev.php?id=32231March 201
Contribution of Information and Communication Technology (ICT) in Country’S H-Index
Get PDFThe aim of this study is to examine the effect of Information and Communication Technology (ICT) development on country’s scientific ranking as measured by H-index. Moreover, this study applies ICT development sub-indices including ICT Use, ICT Access and ICT skill to find the distinct effect of these sub-indices on country’s H-index. To this purpose, required data for the panel of 14 Middle East countries over the period 1995 to 2009 is collected. Findings of the current study show that ICT development increases the H-index of the sample countries. The results also indicate that ICT Use and ICT Skill sub-indices positively contribute to higher H-index but the effect of ICT access on country’s H-index is not clear
Distributed H∞-consensus filtering for target state tracking over a wireless filter network with switching topology, channel fading and packet dropouts
No full textThis paper is concerned with the problem of distributed H∞-consensus filtering for target state tracking over a wireless filter network. The wireless filter network consists of a large number of filter nodes. The network topology is supposed to be switching or changeable over time. Data communication between filter nodes is subject to some network-induced constraints including packet dropouts and channel fading. Different from some existing results, packet dropouts and channel fading are assumed to occur not only in the measurement process for sensors but also in the transmission process among filter nodes. Within such settings, a distributed H∞-consensus filtering method is developed to ensure both the estimation accuracy of filters and the robustness of the filtering error system against network-induced constraints. Criteria on designing desired distributed H∞ consensus-based filter are derived in terms of a set of linear matrix inequalities. Numerical examples are given to verify the effectiveness of the proposed target state tracking filtering algorithm.Full Tex
A survey of handover algorithms in DVB-H
No full textDigital Video Broadcasting for Handhelds (DVB-H) is a standard for
broadcasting IP Datacast (IPDC) services to mobile handheld terminals.
Based on the DVB-T standard, DVB-H adds new features such as time
slicing, MPE-FEC, in-depth interleavers, mandatory cell id identifier,
optional 4K-modulation mode and the use of 5 MHz bandwidth in addition
to the usually used 6, 7, or 8 MHz raster. IPDC over DVB-H is proposed
for ETSI to complement the DVB-H standard by combining IPDC and
DVB-H in an end-to-end system. Handover in such unidirectional broadcasting
networks is a novel issue. In the last few years since the birth of
DVB-H technology, great attention has been given to the performance
analysis of DVB-H mobile terminals. Handover is one of the main research
topics for DVB-H in mobile scenarios. Better reception quality and greater
power efficiency are considered to be the main targets of handover
research for DVB-H. New algorithms for different handover stages in
DVB-H have been the subject of recent research and are currently being
studied. Further novel algorithms need to be designed to improve the
mobile reception quality. This article provides a comprehensive survey of
the handover algorithms in DVB-H. A systematic evaluation and categorization
approach is proposed based on the problems the algorithms solve
and the handover stages being focused on. Criteria are proposed and analyzed
to facilitate designing better handover algorithms for DVB-H that
have been identified from the research conducted by the author
Syntheses and structural characterization of a LAl(N-3)N[mu-Si(N-3)(tBu)](2)NAl(N-3)L and a monomeric aluminum hydride amide LAlH(NHAr) (L=HC[(CMe)(NAr)](2), Ar=2,6-iPr(2)C(6)H(3))
No full textReactions between the aluminum(I) monomer LAl (L = HC[(CMe)(NAr)](2), Ar = 2,6iPr(2)C(6)H(3)) and organic azides (RN3, R = C10H15 (adamantyl), Ph3Si; tBuSi(N-3)3) are reported. LAl reacted with the bulky azide RN3 in toluene in a temperature range of -50 to 25 degrees C, resulting in the compound LAl[(NR)(2)N-2] (R = C10H15 (1), Ph3Si (2)) instead of the expected Al=N multiple bond species, while the reaction with tBuSi(N-3)(3) gave LAl(N-3)N[(mu-Si(N-3)(tBu)](2)NAl(N-3)L (3). Compounds 1-3 have been fully characterized by mass spectrometry and IR and multinuclear NMR spectroscopy (H-1, C-13, and Si-29) as well as by single-crystal X-ray crystallography. The structural analysis of 1 and 2 reveals an AlN4 planar five-membered ring compound, suggesting a [2 + 3] cycloaddition of the Al=N multiple bond species with a molecule of RN3 despite the steric bulk of the L and R substituents. Compound 3 shows a bonding of the N3 group to the Al and a formation of the N2Si2 central core, implying the migration of N3 and a [2 + 2] cycloaddition in the reaction sequence. In addition, the solvent-free reaction of an aluminum dihydride LAlH2 with ArNH2 was also investigated at elevated temperatures (150-290 C), and a monomeric aluminum hydride amide, LAIH(NHAr) (4), was obtained as the only isolable product. The Al-H and N-H groups of 4 are shown in the IR and H-1 NMR spectra. The corresponding X-ray structural analysis exhibits the Al-H and N-H bonds that are nearly arranged in position trans to the Al-N-NHAr bond
Mixed H(2)/H(∞) Robust Guidance Law Design
No full text[[abstract]]A mixed H(2)/H(∞) optimal control design and its application to a missile guidance problem of homing phase are studied. The problem consists of combining the performance requirements of quadratic optimal controllers with the robustness properties of H(2) controllers. Our approach has five features. (l)The complete nonlinear kinematics of the pursuit-evasion motion is considered; neither linearization nor small angle assumption is made here. (2) The nonlinear H(2)/H(∞) guidance law is derived analytically and express in a very simple form; neither iterative approximation nor complicated numerical computation is required. (3) Unlike adaptive and neural guidance laws, the implement of the proposed robust H(2)/H(∞) guidance law does not need the information of target acceleration. (4) Under appropriate constraints, the pair of cross-coupled Hamilton-Jacobi Partial Inequality (HJPDI) can be solved easily. (5) The derived nonlinear H(2)/H(∞) guidance law exhibits string robustness and excellent performance against intelligent adversary aircrafts
ROBUST STABILITY, STABILISATION AND H-INFINITY CONTROL FOR PREMIUM-RESERVE MODELS IN A MARKOVIAN REGIME SWITCHING DISCRETE-TIME FRAMEWORK
Get PDFThe premium pricing process and the medium- and long-term stability of the reserve policy under conditions of uncertainty present very challenging issues in relation to the insurance world. Over the last two decades, applications of Markovian regime switching models to finance and macroeconomics have received strong attention from researchers, and particularly market practitioners. However, relatively little research has so far been carried out in relation to insurance. This paper attempts to consider how a linear Markovian regime switching system in discrete-time could be applied to model the medium- and long-term reserves and the premiums (abbreviated here as the P-R process) for an insurer. Some recently developed techniques from linear robust control theory are applied to explore the stability, stabilisation and robust H∞-control of a P-R system, and the potential effects of abrupt structural changes in the economic fundamentals, as well as the insurer's strategy over a finite time period. Sufficient linear matrix inequality conditions are derived for solving the proposed sub-problems. Finally, a numerical example is presented to illustrate the applicability of the theoretical results
Contribution of Information and Communication Technology (ICT) in Country’S H-Index
Get PDFThe aim of this study is to examine the effect of Information and Communication Technology (ICT) development on country’s scientific ranking as measured by H-index. Moreover, this study applies ICT development sub-indices including ICT Use, ICT Access and ICT skill to find the distinct effect of these sub-indices on country’s H-index. To this purpose, required data for the panel of 14 Middle East countries over the period 1995 to 2009 is collected. Findings of the current study show that ICT development increases the H-index of the sample countries. The results also indicate that ICT Use and ICT Skill sub-indices positively contribute to higher H-index but the effect of ICT access on country’s H-index is not clear.Cite as:
FARHADI, M., SALEHI, H., EMBI, M. A., FOOLADI, M., FARHADI, H., AGHAEI CHADEGANI, A., & ALE EBRAHIM, N. (2013). Contribution of Information and Communication Technology (ICT) in Country’S H-Index. Journal of Theoretical and Applied Information Technology, 57(1), 122-127
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