Maximum-likelihood estimator for coarse carrier frequency offset estimation in OFDM systems

Orthogonal frequency division multiplexing (OFDM) systems are more sensitive to carrier frequency offset (CFO) compared to the conventional single carrier systems. CFO destroys the orthogonality among subcarriers, resulting in inter-carrier interference (ICI) and degrading system performance. To mitigate the effect of the CFO, it has to be estimated and compensated before the demodulation. The CFO can be divided into an integer part and a fractional part. In this paper, we investigate a maximum-likelihood estimator (MLE) for estimating the integer part of the CFO in OFDM systems, which requires only one OFDM block as the pilot symbols. To reduce the computational complexity of the MLE and improve the bandwidth efficiency, a suboptimum estimator (Sub MLE) is studied. Based on the hypothesis testing method, a threshold Sub MLE (T-Sub MLE) is proposed to further reduce the computational complexity. The performance analysis of the proposed T-Sub MLE is obtained and the analytical results match the simulation results well. Numerical results show that the proposed estimators are effective and reliable in both additive white Gaussian noise (AWGN) and frequency-selective fading channels in OFDM systems.

A discussion on design exhibition "delivery to Sichuan" - interview with Tie Fan, senior architect at Foster & Partners

By the British "East Design Alliance" (West East Design Group) was launched, entitled "Sichuan Express" (Delivery to Sichuan) earthquake relief concept design exhibition in September 2008 from 1 to 5 at the Alan Baxter gallery...

UK green building development: investigation of the green architecture development in the UK

This paper reviews the background of green building, content and evaluation system, and on this basis, focuses on the development of the UK Green Building and the latest trends and development of green buildings in China's cause of enlightenment

The Complete Works of John Milton: Volume III: The Shorter Poems (816pp.)

Volume III of the new eleven-volume edition of Milton's Complete Works provides a definitive scholarly edition of all of Milton's shorter poems in English, Latin, Italian, and Greek, as well as his Mask, taken from both published and manuscript sources. It includes his 1645 Poems complete with all prefatory materials, thus illuminating the ways in which author, publisher, and print shop shaped this volume. It then presents all the new poems added in the 1673 edition (with the new Table of Contents), as well as the poems omitted from both editions. A careful collation of textual variants among these sources as well as the 1637 anonymous publication of Milton's Mask is provided. The Bridgewater manuscript of Milton's Mask (probably close to the acting version) and his working copy from the Trinity Manuscript, with its many alterations and additions, are transcribed in their entirety, so that the various versions may be compared and studied. 

A special feature of this edition is a new translation of Milton's many Latin and Greek poems that is both accurate and attentive to their literary qualities. This is augmented by a detailed and comprehensive commentary that highlights classical, vernacular, and neo-Latin parallels. A poetic translation of Milton's six Italian sonnets and Canzone is also supplied. In addition, the Appendices contain all the versions of Milton's shorter poems in all the contemporary manuscript and printed sources, so they may be examined in relation to their specific contexts. The transcription of all the versions of Milton's poems in the Trinity Manuscript allows in several cases, notably 'Lycidas' and 'At a Solemn Music,' for examination of the evolution of these poems as Milton weighed choiced of diction and sound qualities, enabling further understanding of his poetic practices. 

Barbara Lewalski is responsible for text, textual apparatus, and commentary pertaining to the vernacular poems in all sections of this edition including the appendices, and manuscript transcriptions (with the exception of A Maske), as well as the Occasions, Vernacular Poems,and Textual Introductions. Estelle Haan is responsible for text, textual apparatus, and commentary for the Poemata in all sections of this edition,and for the Poemata Introduction. She has also provided all translations from Latin, Italian, and Greek in the Testimonia, Poemata, and associated commentary, and transcriptions of the BL Damon, the Bodleian AdJoannem Rousium, and A Maske from the Trinity and Bridgewater manuscripts. Andrew McNeillie has provided poetic translations for Milton’s Italian sonnets, and Jason Rosenblatt has provided some Hebrew text and commentary pertaining to Milton’s Psalm translations.John Cunningham has transcribed Henry Lawes’ music for Milton’s masque, with commentary (Appendix E). Biblical references are taken from the King James (Authorized) Version.

Energetic costs of parasitism in the Cape ground squirrel Xerus inauris

Parasites have been suggested to influence many aspects of host behaviour. Some of these effects may be mediated via their impact on host energy budgets. This impact may include effects on both energy intake and absorption as well as components of expenditure, including resting metabolic rate (RMR) and activity (e.g. grooming). Despite their potential importance, the energy costs of parasitism have seldom been directly quantified in a field setting. Here we pharmacologically treated female Cape ground squirrels (Xerus inauris) with anti-parasite drugs and measured the change in body composition, the daily energy expenditure (DEE) using doubly labelled water, the RMR by respirometry and the proportions of time spent looking for food, feeding, moving and grooming. Post-treatment animals gained an average 19 g of fat or approximately 25 kJ d(-1). DEE averaged 382 kJ d-1 prior to and 375 kJ d-1 post treatment (p> 0.05). RMR averaged 174 kJ d-1 prior to and 217 kJ d-1 post treatment (p

Neural network based control for synchronous generators

In this paper, a Radial Basis Function neural network based AVR is proposed. A control strategy which generates local linear models from a global neural model on-line is used to derive controller feedback gains based on the Generalised Minimum Variance technique. Testing is carried out on a micromachine system which enables evaluation of practical implementation of the scheme. Constraints imposed by gathering training data, computational load, and memory requirements for the training algorithm are addressed.

"Cómo pintar el aire". Fundamentos científicos de la perspectiva atmosférica

La perspectiva aérea o atmosférica es juzgada por los pintores como parte esencial de la pintura, una vez establecidos los presupuestos geométricos de la representación naturalista mediante la perspectiva lineal. Leonardo da Vinci fue el primer autor en definir la perspectiva aérea o atmosférica, conocidos ya a través de L. B. Alberti los fundamentos geométricos de la perspectiva lineal en el tratado De Pictura (1435). Doscientos años después, tras la influyente publicación del Optics de Newton, contextualizadas bajo el espíritu racionalista del siglo XVIII, el artículo estudia las recomendaciones que desde la ciencia y los científicos (específicamente a través de tres figuras relevantes: Brook Taylor, J. H. Lambert y Gaspard Monge) se dan a los pintores con la pretensión de arbitrar una medición exacta del color, en confrontación con el tradicional empirismo del mundo artístico. Este tema puede considerarse un capítulo de gran interés en la larga historia de la pintura y la representación de los fenómenos atmosféricos, cuyos antecedentes teóricos tienen su inicio en el Débat sur le Coloris de la Académie Française del siglo XVII y sus resultados, conducirán hacia el nacimiento de la moderna Teoría del color, en respuesta a una cuestión tan compleja sobre cómo pintar el aire.

Estimating the masses of extra-solar planets

All extra-solar planet masses that have been derived spectroscopically are lower limits since the inclination of the orbit to our line-of-sight is unknown except for transiting systems. In theory, however, it is possible to determine the inclination angle, i, between the rotation axis of a star and an observer's line-of-sight from measurements of the projected equatorial velocity (v sin i), the stellar rotation period (P(rot)) and the stellar radius (R(*)). For stars which host planetary systems this allows the removal of the sin i dependency of extra-solar planet masses derived from spectroscopic observations under the assumption that the planetary orbits lie perpendicular to the stellar rotation axis.
We have carried out an extensive literature search and present a catalogue of v sin i, P(rot) and R(*) estimates for stars hosting extra-solar planets. In addition, we have used Hipparcos parallaxes and the Barnes-Evans relationship to further supplement the R(*) estimates obtained from the literature. Using this catalogue, we have obtained sin i estimates using a Markov-chain Monte Carlo analysis. This technique allows proper 1 Sigma two-tailed confidence limits to be placed on the derived sin i's along with the transit probability for each planet to be determined.
While we find that a small proportion of systems yield sin i's significantly greater than 1, most likely due to poor P(rot) estimations, the large majority are acceptable. We are further encouraged by the cases where we have data on transiting systems, as the technique indicates inclinations of similar to 90 degrees and high transit probabilities. In total, we are able to estimate the true masses of 133 extra-solar planets. Of these 133 extra-solar planets, only six have revised masses that place them above the 13M(J) deuterium burning limit; four of those six extra-solar planet candidates were already suspected to lie above the deuterium burning limit before correcting their masses for the sin i dependency. Our work reveals a population of high-mass extra-solar planets with low eccentricities, and we speculate that these extra-solar planets may represent the signature of different planetary formation mechanisms at work. Finally, we discuss future observations that should improve the robustness of this technique.

Tri- and tetra-substituted naphthalene diimides as potent G-quadruplex ligands.

A series of tri- and tetra-substituted naphthalene diimides have been designed and synthesized. Several compounds show exceptional affinity for telomeric G-quadruplex DNA in classical and competition FRET assays and SPR studies. They inhibit telomerase in the TRAP assay, and show potent senescence-based short-term anti-proliferative effects on MCF7 and A549 cancer cell lines, and localize in the nucleus and particularly the nucleolus of MCF7 cells.