110,042 research outputs found
A Wideband Radial Basis Function Decision Feedback Equaliser Assisted Burst-by-Burst Adaptive Modem
No full textThe performance of radial basis function-based decision feedback equalized (RBF DFE) burst-by-burst adaptive quadrature amplitude modulation (AQAM) is presented for transmissions over dispersive wide-band mobile channels. This scheme is shown to give a significant improvement in terms of the mean bit error rate (BER) and bits per symbol (BPS) performance compared to that of the individual fixed modulation modes. The structural equivalence of the RBF DFE to the optimal Bayesian equalizer enables it to potentially outperform the conventional Kalman-filtered AQAM DFE scheme. Index Terms—Adaptive modulation, decision feedback equalization, radial basis function, wide-band modem
Student Expectations in the New Millennium
No full textHigher education has experienced vast changes as a result of global political and economic developments. Cultural and social changes in the last decade have also added to the continuing evolution of higher education. These changes inevitably lead to changing expectations of students entering higher education. An adequate understanding of student expectations is crucial in ensuring a good fit between higher educational institutions and their students. This study attempts to carry out a baseline descriptive-quantitative research on student expectations in the higher education of Hong Kong. Four scales have been developed to measure students’ attitude toward: 1. job-oriented curriculum design, 2. user-friendly course delivery method, 3. opportunities for lifelong learning, and 4. student consumerism. Students’ priority of what makes a good university, their reasons for going to university, and their self-perception of ability to cope with university life are also explored. The Student Expectations Questionnaire (developed by the author) was used to gather data from 857 first-year undergrads from nine institutions of higher education in Hong Kong. Analyses include, among others, gender, age, major of study as well as institution comparisons
Quality of life and willingness-to-pay for dental extractions among Singaporean-elderly
No full textPoster abstract 188R. Nair, R. Yee Ting Fai, S. Liang, and G. Tsako
Entropy splitting for high-order numerical simulation of compressible turbulence
No full textA stable high-order numerical scheme for direct numerical simulation (DNS) of shock-free compressible turbulence is presented. The method is applicable to general geometries. It contains no upwinding, artificial dissipation, or filtering. Instead the method relies on the stabilizing mechanisms of an appropriate conditioning of the governing equations and the use of compatible spatial difference operators for the interior points (interior scheme) as well as the boundary points (boundary scheme). An entropy-splitting approach splits the inviscid flux derivatives into conservative and nonconservative portions. The spatial difference operators satisfy a summation-by-parts condition, leading to a stable scheme (combined interior and boundary schemes) for the initial boundary value problem using a generalized energy estimate. A Laplacian formulation of the viscous and heat conduction terms on the right hand side of the Navier–Stokes equations is used to ensure that any tendency to odd–even decoupling associated with central schemes can be countered by the fluid viscosity. The resulting methods are able to minimize the spurious high-frequency oscillations associated with pure central schemes, especially for long time integration applications such as DNS. For validation purposes, the methods are tested in a DNS of compressible turbulent plane channel flow at low values of friction Mach number, where reference turbulence data bases exist. It is demonstrated that the methods are robust in terms of grid resolution, and in good agreement with published channel data. Accurate turbulence statistics can be obtained with moderate grid sizes. Stability limits on the range of the splitting parameter are determined from numerical tests
Radial Basis Function Assisted Turbo Equalization
No full textThis paper presents a turbo equalization (TEQ) scheme, which employs a radial basis function (RBF)-based equalizer instead of the conventional trellis-based equalizer of Douillard et al. Structural, computational complexity, and performance comparisons of the RBF-based and trellis-based TEQs are provided. The decision feedback-assisted RBF TEQ is capable of attaining a similar performance to the logarithmic maximum scheme in the context of both binary phase-shift keying (BPSK) and quaternary phase-shift keying (QPSK) modulation, while achieving a factor 2.5 and 3 lower computational complexity, respectively. However, there is a 2.5-dB performance loss in the context of 16 quadrature amplitude modulation (QAM), which suffers more dramatically from the phenomenon of erroneous decision-feedback effects. A novel element of our design, in order to further reduce the computational complexity of the RBF TEQ, is that symbol equalizations are invoked at current iterations only if the decoded symbol has a high error probability. This techniques provides 37% and 54% computational complexity reduction compared to the full-complexity RBF TEQ for the BPSK RBF TEQ and 16QAM RBF TEQ, respectively, with little performance degradation, when communicating over dispersive Rayleigh fading channels. Index Terms—Decision-feedback equalizer (DFE), Jacobian logarithm, neural network, radial basis function (RBF), turbo coding, turbo equalization (TEQ)
Burst-by-Burst Adaptive Turbo-Coded Radial Basis Function-Assisted Decision Feedback Equalization
No full textThe performance of the proposed radial basis function (RBF) assisted turbo-coded adaptive modulation scheme is characterized in a wideband channel scenario. We commence by introducing the novel concept of the Jacobian RBF equalizer, which is a reduced-complexity version of the conventional RBF equalizer. Specifically, the Jacobian logarithmic RBF equalizer generates its output in the logarithmic domain and hence it can be used to provide soft outputs for the turbo-channel decoder. We propose using the average magnitude of the log-likelihood ratio (LLR) of the bits in the received transmission burst before channel decoding as the channel quality measure for controlling the mode-switching regime of our adaptive scheme
Taxonomy and biogeography of Sundaland Gardenia (Rubiaceae) / Low Yee Wen
No full textIn Southeast Asia, the genus Gardenia J.Ellis (Rubiaccae) is poorly understood and documented due to a lack of country revisions, contentious species delimitations and accumulation of poorly identified material in herbaria. This study reviewed the taxonomic history and position of the genus, and revised the taxonomy of Sundaland species (including those of Sumatra. the Malay Peninsula, Java_ Borneo, Palawan and adjacent islands). It includes a survey and cladistic study of morphological characteristics, and phylogenetic ana lyses using two chloroplast regions (atpB-rbcL and trnT-F) and the nuclear ITS region of representative species from Sundaland and adjoining regions. Twelve species are native to Sundaland and another two from mainland Asia and Wallacea commonly cultivated. Important generic characters include a woody shrub to tree habit with the growth architectural models of Leeuwen berg and Scarrone; resinous buds; tubular stipules; so litary terminal nowers; and pollen in tetracls. Calyx characters were the most use ful for species di stinction. Comparative morphological studies allowed two very closely related species, G. e/ata and G. tubijera, to be distinguished; G. tubi}era var. subcarinuta to be raised to species rank; and G. c/o/ichantha to be subsumed under the synonymy of G. griffithii. Several new species (G. beamanii Y. W.Low and G. chanii Y. W.Low) and varieties (G . . rnbcarinata var. sumatrcnia Y. W.Low and G. el at a var. kinaba/ue11sis ined.) were diagnosed. An identification key to Sundaland taxa, species descriptions, notes and identification lists are provided. The genealogies produced showed that Sundaland lineages were largely distinct from mainland Asian ones, probably renecting the biogeographic distinction of these regions. Limited introgression of the mainland lineage including G. jasminoides into the lineage with G. chanii was detected. There was evidence for reticulate evolution among Sundaland lineages indicated by discordant genealogies of chloroplast and nuclear regions. lntrogression of the widespread Sundaland species G. elata into a lineage with Lhe more locally restricted G. Beamanii (Borneo) was probably enabled by increased chances of contact during Pleistocene sealevel rn inima, when lowland forest area was contiguous between present-day Peninsular Malaysia and Borneo. Local variation in genetic characteristics implies that current for rest fragmentation in Sundaland could dimini sh the species va riab ility of G. elata. A complex of rarer species mostly occurring in pockets in peat swamps (G. chanii, G. griflthii, G. pteroca/yx, G. tubifera) and adjacent kerangas fo rests (G. cosllllata) would also be threatened by habitat disturbance and transformation
Turbo Equalization of Convolutional Coded and Concatenated Space Time Trellis Coded Systems using Radial Basis Function Aided Equalizers
No full textIn this contribution a reduced-complexity radial basis function (RBF) aided neural-network based turbo equalization (TEQ) scheme is proposed for employment in a serially concatenated convolutional coded and systematic space time trellis coded (CC-SSTTC) arrangement. A two-path Rayleigh fading channel having a normalised Doppler frequency of 3.3615 x l0E-05 was used. The BER performance of the RBF-CC-SSTTC(4,4) scheme employing a transmission burst consisting of 100 symbols using a space-time-trellis (STT) interleaver of at least 400 symbols and eight turbo equalization iterations was found to be similar to that of the CC-SSTTC system using a trellis-based TEQ, which attains the optimum performance. However, the Jacobian RBF based TEQ provided a complexity reduction factor of 14
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Connecting practice to research (and back to practice): making the leap from design practice to design research
No full textThis paper explores two questions: what skills and knowledge can be derived from research and brought back into design practice; and how can we better prepare designers to undertake research?
Its aim was to enable design practitioners wishing to pursue research to understand the process and anticipate the scope and level of work. Additionally, it addressed the questions of how design education can incorporate a research-based curriculum and how professional bodies can promote the value of research to practitioners?
A complementary paper was co-written and presented at the CONNECTED 07 conference, Sydney. It explores the process of undertaking a PhD within the framework of the UK design education system by examining it from a design and business perspective (Yee, J.S.R, Michlewski, K. and Bohemia, E. (2007) 'Interrogating the Academic Research Process in UK Design Education from Design and Business Perspectives', ConnectED 2007 – International Conference on Design Education, Sydney, (http://www.designdictator.com/publications/connected07.pdf). Yee’s research bridges the gap between contemporary design practice, the growth of professional knowledge and pedagogy, via empirical study and theoretical discourse. Yee is currently 2nd supervisor for a PhD, entitled; ‘The Development of a Framework to Understand Potential Relationships Between Services and Their Users’ and is contributing to the development of the Professional Practice Doctorate in Design in the CfDR
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