Soliton mode locking fiber laser with an all-fiber polarization interference filter

An erbium doped fiber ring laser achieving soliton mode locking by the use of an intra-cavity all-fiber polarization interference filter (AFPIF) has been demonstrated. To incorporate an AFPIF with relative narrow transmission bandwidth, the laser has produced clean soliton pulses of 1.2 ps duration at a repetition rate of 14.98 MHz with a polarization extinction ratio up to 25.7 dB. Moreover, we have demonstrated that the operating wavelength of the mode locking laser can be tuned over 20 nm range from 1545 to 1565 nm by thermally tuning the AFPIF cavity. © 2012 Optical Society of America.

Looking back or looking forward in corpus linguistics:what can the last 20 years suggest about the next?

Starting with a description of the software and hardware used for corpus linguistics in the late 1980s to early 1990s, this contribution discusses difficulties faced by the software designer when attempting to allow users to study text. Future human-machine interfaces may develop to be much more sophisticated, and certainly the aspects of text which can be studied will progress beyond plain text without images. Another area which will develop further is the study of patternings involving not just single words but word-relations across large stretches of text.

Reductions of peak-to-average power ratio and optical beat interference in cost-effective OFDMA-PONs

The peak-to-average power ratio (PAPR) and optical beat interference (OBI) effects are examined thoroughly in orthogonal frequency-division multiplexing access (OFDMA)-passive optical networks (PONs) at a signal bit rate up to ∼ 20 Gb/s per channel using cost-effective intensity-modulation and direct-detection (IM/DD). Single-channel OOFDM and upstream multichannel OFDM-PONs are investigated for up to six users. A number of techniques for mitigating the PAPR and OBI effects are presented and evaluated including adaptive-loading algorithms such as bit/power-loading, clipping for PAPR reduction, and thermal detuning (TD) for the OBI suppression. It is shown that the bit-loading algorithm is a very efficient PAPR reduction technique by reducing it at about 1.2 dB over 100 Km of transmission. It is also revealed that the optimum method for suppressing the OBI is the TD + bit-loading. For a targeted BER of 1 × 10-3, the minimum allowed channel spacing is 11 GHz when employing six users. © 2013 Springer Science+Business Media New York.

Nonlinear refraction in optical lattices induced by the wave-soliton interference

In the framework of 1D Nonlinear Shrödinger Equation (NSE) we demonstrate how one can control the refractive angle of a fundamental soliton beam passing through an optical lattice, by adjusting either the shape of an individual waveguide or the relative positions of waveguides. Even for a single scatterer its shape has a nontrivial effect on the refraction direction. In the case of shallow modulation we provide an analytical description based of the effect on the soliton perturbation theory. When one considers a lattice of scatterers, there emanates an additional form factor in the radiation density (RD) of emitted waves referring to the wave-soliton beating and interference inside the lattice. We concentrate on the results for two cases: periodic lattice and disordered lattice of scattering shapes. © 2011 IEEE.

French linguistics research and teaching in UK and Irish HE institutions

Introduction: The research and teaching of French linguistics in UK higher education (HE) institutions have a venerable history; a number of universities have traditionally offered philology or history of the language courses, which complement literary study. A deeper understanding of the way that the phonology, syntax and semantics of the French language have evolved gives students linguistic insights that dovetail with their study of the Roman de Renart, Rabelais, Racine or the nouveau roman. There was, in the past, some coverage of contemporary French phonetics but little on sociolinguistic issues. More recently, new areas of research and teaching have been developed, with a particular focus on contemporary spoken French and on sociolinguistics. Well supported by funding councils, UK researchers are also making an important contribution in other areas: phonetics and phonology, syntax, pragmatics and second-language acquisition. A fair proportion of French linguistics research occurs outside French sections in psychology or applied linguistics departments. In addition, the UK plays a particular role in bringing together European and North American intellectual traditions and methodologies and in promoting the internationalisation of French linguistics research through the strength of its subject associations, and that of the Journal of French Language Studies. The following sections treat each of these areas in turn. History of the French Language There is a long and distinguished tradition in Britain of teaching and research on the history of the French language, particularly, but by no means exclusively, at the universities of Cambridge, Manchester and Oxford.

Exploiting heterogeneous scientific literature networks to combat ranking bias:evidence from the computational linguistics area

It is important to help researchers find valuable papers from a large literature collection. To this end, many graph-based ranking algorithms have been proposed. However, most of these algorithms suffer from the problem of ranking bias. Ranking bias hurts the usefulness of a ranking algorithm because it returns a ranking list with an undesirable time distribution. This paper is a focused study on how to alleviate ranking bias by leveraging the heterogeneous network structure of the literature collection. We propose a new graph-based ranking algorithm, MutualRank, that integrates mutual reinforcement relationships among networks of papers, researchers, and venues to achieve a more synthetic, accurate, and less-biased ranking than previous methods. MutualRank provides a unified model that involves both intra- and inter-network information for ranking papers, researchers, and venues simultaneously. We use the ACL Anthology Network as the benchmark data set and construct the gold standard from computer linguistics course websites of well-known universities and two well-known textbooks. The experimental results show that MutualRank greatly outperforms the state-of-the-art competitors, including PageRank, HITS, CoRank, Future Rank, and P-Rank, in ranking papers in both improving ranking effectiveness and alleviating ranking bias. Rankings of researchers and venues by MutualRank are also quite reasonable.

The Routledge handbook of forensic linguistics

The Routledge Handbook of Forensic Linguistics provides a unique work of reference to the leading ideas, debates, topics, approaches and methodologies in Forensic Linguistics. Forensic Linguistics is the study of language and the law, covering topics from legal language and courtroom discourse to plagiarism. It also concerns the applied (forensic) linguist who is involved in providing evidence, as an expert, for the defence and prosecution, in areas as diverse as blackmail, trademarks and warning labels. The Routledge Handbook of Forensic Linguistics includes a comprehensive introduction to the field written by the editors and a collection of thirty-seven original chapters written by the world’s leading academics and professionals, both established and up-and-coming, designed to equip a new generation of students and researchers to carry out forensic linguistic research and analysis. The Routledge Handbook of Forensic Linguistics is the ideal resource for undergraduates or postgraduates new to the area.

Forensic linguistics : the application of language description in legal contexts

In this article I first divide Forensic Linguistics into three sub-disciplines: the language of written legal texts, the spoken language of legal proceedings, and the linguist as expert witness and then go on to give a small number of examples of the research undertaken in these three areas. For the language of written legal texts, I present work on the (in) comprehensibility of police cautions and of judges instructions to juries. For the spoken language of legal proceedings, I report work on the problems of interpreted interaction, of vulnerable witnesses and the need for more detailed research comparing the interactive rules in adversarial and investigative systems. Finally, to illustrate the role of the linguist as expert witness I report a trademark case, five different authorship attribution cases, three very different plagiarism cases and I end reporting briefly the contribution of linguists to language assessment techniques used in the linguistic classification of asylum seekers. © Langage et société no 132 - juin 2010.