Optimization of Passive and Hybrid Mode-locked Figure Eight Laser

In pulsed fiber laser using Q-switching or mode locking techniques, the choice of the different components and the management of linear and non linear parameters of the cavity, play a paramount role in the generation of stable ultra short pulses with high peak powers and low widths. In this paper, we focus on the operating process of mode locked fiber lasers especially passively and hybrid type Eight Fiber Lasers (8FLs). By modeling the light propagation within the two cavities, we describe the whole operating process of ultra short pulses generation. The interaction between the mode locking mechanism and nonlinear effects in fiber laser is also illustrated. We demonstrate enhancing non linear effects do not lead necessarily to better results. It depends on the type of mode locking techniques used. The highest and narrowest output pulses are obtained for specific values of the non linear parameters and the mean dispersion of the cavity

Perceived health and quality of life: the effect of exposure to atmospheric pollution

International audienc

Acceleration of Python Applications on GPU

Konvenčne sa v oblasti high performance computing (HPC) používajú prekladané jazyky, ako napríklad C++. Skriptovacie jazyky ako Python sú však pohodlnejšie a vývoj aplikácií je v nich rýchlejší a jednoduchší. Táto práca porovnáva jazyky C++ a Python z hľadiska možnosti akcelerácie výpočtov na grafickej karte. Jej cieľom je ukázať, že skriptovacie jazyky sú taktiež použiteľné na implementáciu HPC aplikácií a poukázať na ich výhody a nevýhody oproti prekladaným jazykom. Za týmto účelom je implementovaných niekoľko programov. Tie pozostávajú z niekoľkých menších testovacích programov a jedného väčšieho programu, riešiaceho výpočtovo náročný problém. Implementácie týchto programov v jazykoch C++ a Python sú porovnané ako z hľadiska výkonu, tak z hľadiska náročnosti implementácie.Compiled languages, such as C++, are conventionally used in the field of high performance computing (HPC). However, scripting languages like Python are more convenient and application development is quicker and simpler in these languages. This work compares C++ and Python in terms of the possibilities of computation acceleration on graphics card. Its aim is to show that scripting languages are also suitable for the implementation of HPC applications, and point out their advantages and disadvantages compared to compiled languages. To this purpose, a number of programs have been implemented. Several smaller programs for testing purposes and a larger one, implementing a computationally intensive problem. The implementations of these programs in C++ and Python are compared in terms of performance, as well as difficulty of implementation.

Towards Comprehensive Computational Representations of Arabic Multiword Expressions

A successful computational treatment of multiword expressions (MWEs) in natural languages leads to a robust NLP system which considers the long-standing problem of language ambiguity caused primarily by this complex linguistic phenomenon. The first step in addressing this challenge is building an extensive reliable MWEs language resource LR with comprehensive computational representations across all linguistic levels. This forms the cornerstone in understanding the heterogeneous linguistic behaviour of MWEs in their various manifestations. This paper presents a detailed framework for computational representations of Arabic MWEs (ArMWEs) across all linguistic levels based on the state-of-the-art lexical mark-up framework (LMF) with the necessary modifications to suit the distinctive properties of Modern Standard Arabic (MSA). This work forms part of a larger project that aims to develop a comprehensive computational lexicon of ArMWEs for NLP and language pedagogy LP (JOMAL project)

Dust-Acoustic Solitary Waves in Magnetized Dusty Plasma with Dust Opposite Polarity

The nonlinear propagation of small but finite amplitude dust-acoustic solitary waves (DAWs) in magnetized collision less dusty plasma has been investigated. The fluid model is a four component magnetized dusty plasma, consisting of positive and negative dust species, isothermal electrons and ions in the presence of an external magnetic field. A reductive perturbation method was employed to obtain the Zakharov Kuznetsov (ZK) equation for the first-order potential. The effects of the presence of positively charged dust fluid, the external magnetic field, and the obliqueness are obtained. The results of the present investigation may be applicable to some plasma environments, such as cometary tails, upper mesosphere and Jupiter\u27s magnetosphere

The relationship between consumer ethnocentrism, cosmopolitanism and product country image among younger generation consumers: the moderating role of country development status

Although the differences between developed and developing countries have been extensively studied in the context of globalization strategies, few studies have so far been conducted on the relationship between country development status and the possession by countries of a favorable (or unfavorable) product country image (PCI). Moreover, the results of such studies to date have been inconclusive. The purpose of this paper is to investigate the moderating role of country developmental status on PCI coupled with two antecedents of PCI, namely consumer ethnocentrism and cosmopolitanism. The paper also distinguishes between the PCI of the home and foreign country images of respondents. We test a new model that incorporates these constructs with a sample of 2655 younger generation consumers. The results show that country development status moderates some relationships but does not moderate others. These findings have significant implications for international companies from both developed and developing countries when developing global strategy

Development and Validation of an Environmental Quality of Life Scale: Study of a French Sample

International audienc

Minimally invasive versus conventional aortic valve replacement: a propensity-matched study from the UK National Data

Minimally invasive aortic valve replacement (MIAVR) has been demonstrated as a safe and effective option but remains underused. We aimed to evaluate outcomes of isolated MIAVR compared with conventional aortic valve replacement (CAVR).Data from The National Institute for Cardiovascular Outcomes Research (NICOR) were analyzed at seven volunteer centers (2006-2012). Primary outcomes were in-hospital mortality and midterm survival. Secondary outcomes were postoperative length of stay as well as cumulative bypass and cross-clamp times. Propensity modeling with matched cohort analysis was used.Of 307 consecutive MIAVR patients, 151 (49%) were performed during the last 2 years of study with a continued increase in numbers. The 307 MIAVR patients were matched on a 1:1 ratio. In the matched CAVR group, there was no statistically significant difference in in-hospital mortality [MIAVR, 4/307,(1.3%); 95% confidence interval (CI), 0.4%-3.4% vs CAVR, 6/307 (2.0%); 95% CI, 0.8%-4.3%; P = 0.752]. One-year survival rates in the MIAVR and CAVR groups were 94.4% and 94.6%, respectively. There was no statistically significant difference in midterm survival (P = 0.677; hazard ratio, 0.90; 95% CI, 0.56-1.46). Median postoperative length of stay was lower in the MIAVR patients by 1 day (P = 0.009). The mean cumulative bypass time (94.8 vs 91.3 minutes; P = 0.333) and cross-clamp time (74.6 vs 68.4 minutes; P = 0.006) were longer in the MIAVR group; however, this was significant only in the cross-clamp time comparison.Minimally invasive aortic valve replacement is a safe alternative to CAVR with respect to operative and 1-year mortality and is associated with a shorter postoperative stay. Further studies are required in high-risk (logistic EuroSCORE > 10) patients to define the role of MIAVR