Performance Analysis of Project-and-Forward Relaying in Mixed MIMO-Pinhole and Rayleigh Dual-Hop Channel

In this letter, we present an end-to-end performance analysis of dual-hop project-and-forward relaying in a realistic scenario, where the source-relay and the relay-destination links are experiencing MIMO-pinhole and Rayleigh channel conditions, respectively. We derive the probability density function of both the relay post-processing and the end-to-end signal-to-noise ratios, and the obtained expressions are used to derive the outage probability of the analyzed system as well as its end-to-end ergodic capacity in terms of generalized functions. Applying then the residue theory to Mellin-Barnes integrals, we infer the system asymptotic behavior for different channel parameters. As the bivariate Meijer-G function is involved in the analysis, we propose a new and fast MATLAB implementation enabling an automated definition of the complex integration contour. Extensive Monte-Carlo simulations are invoked to corroborate the analytical results.Comment: 4 pages, IEEE Communications Letters, 201

An exact method for a discrete multiobjective linear fractional optimization

Integer linear fractional programming problem with multiple objective MOILFP is an important field of research and has not received as much attention as did multiple objective linear fractional programming. In this work, we develop a branch and cut algorithm based on continuous fractional optimization, for generating the whole integer efficient solutions of the MOILFP problem. The basic idea of the computation phase of the algorithm is to optimize one of the fractional objective functions, then generate an integer feasible solution. Using the reduced gradients of the objective functions, an efficient cut is built and a part of the feasible domain not containing efficient solutions is truncated by adding this cut. A sample problem is solved using this algorithm, and the main practical advantages of the algorithm are indicated

An exact method for a discrete multiobjective linear fractional optimization

Integer linear fractional programming problem with multiple objective MOILFP is an important field of research and has not received as much attention as did multiple objective linear fractional programming. In this work, we develop a branch and cut algorithm based on continuous fractional optimization, for generating the whole integer efficient solutions of the MOILFP problem. The basic idea of the computation phase of the algorithm is to optimize one of the fractional objective functions, then generate an integer feasible solution. Using the reduced gradients of the objective functions, an efficient cut is built and a part of the feasible domain not containing efficient solutions is truncated by adding this cut. A sample problem is solved using this algorithm, and the main practical advantages of the algorithm are indicated.multiobjective programming, integer programming, linear fractional programming, branch and cut

Modelling thermal effects in agitated vessel and reactor design consideration

The knowledge of the heat transfer coefficient on the inner side of a heated vessel wall is of utmost importance for the design of agitated vessels. The present contribution deals with heat transfer in an agitated vessel containing non-Newtonian liquid. The impellers used are six-blade Turbine (TPD) and a Propeller (TPI). The following aspects are discussed: description of the heat transfer process with the aid of dimensional analysis, heat transfer correlations for agitated liquid and influence of impeller speed on heat transfer

Flux des particules grossières de matière organique allochtone et autochtone dans un bras mort du Rhône

Les flux de matière organique particulaire allochtone et autochtone ont été suivis dans la Lône des Pêcheurs. Leur estimation quantitative et qualitative rend compte de l'impact de l'écotone rives sur le fonctionnement du système aquatique. Dans ce bras mort, les apports allochtones semblent plus importants que dans d'autres systèmes, comme les ruisseaux forestiers mentionnés par la littérature.Pour l'estimation des flux de matière organique particulaire nous avons utilisé, comme moyen d'échantillonnage, des bacs de plastique rectangulaires déposés sur le fond; en plus nous avons procédé à des prélèvements par benne.Le plus grand apport de feuilles terrestres a lieu en novembre, le plus grand apport de bois et autres débris en avril et dans les mois qui suivent, probablement par suite des crues. Au niveau de la lône, on note une différence entre les parties amont et aval.A surface égale, les apports grossiers (feuilles mortes et bois) sont plus abondants en amont, les éléments en voie de désintégration sont, au contraire, plus nombreux en aval. Cette différence est principalement due à la proportion des rives par rapport à la surface du plan d'eau et probablement aussi à la vitesse de dégradation de ces apports dans les deux stations. Ceci nous amène donc à penser qu'il existerait un gradient décroissant de matière organique grossière de l'amont de la lône vers l'aval.La biocénose aquatique est alimentée d'abord par les macrophytes immergés à décomposition rapide (été, automne), puis par les feuilles terrestres et les macrophytes émergés (hiver, printemps).L'analyse de la structure des invertébrés aquatiques montre la relation entre ces apports, particutièrement les feuilles mortes, et la biomasse des dilacérateurs et des collecteurs.This study concerns a side arm of the River Rhone, 20 km upstream from the city of Lyons, southeastern France. The arm opens into the channel of the river downstream, but it is closed and fed by groundwater upstream. Terrestrial particulate organic matter enters the water through the ecotone of the banks. This flow and that of carbon, nitrogen and phosphorus were measured, using sediment traps and a grab, by the monthly sedimentation of allochthonous organic matter on the bottom, corrected for the time of exposure under the water. The input seemed to be somewhat greater than in the temperate woodland streams described in the literature.The greatest input of terrestrial leaves occurred in November, the greatest input of wood and other debris in April, presumably as a consequence of the flooding of the undergrowth. The arm was narrower upstream than downstream (respectively 10-25 and 60-80 m in width). Though the banks were equally and densely forested, the bottom sediment received more coarse particulate matter upstream, and this matter was equally distributed. In contrast, less organic matter was deposited along the banks downstream and still less in the middle of the arm, where partially, decomposed matter was more abundant. These differences may be explained by the ratio between the banks and the water area, by a certain transport during the floods, and by the faster processing of particulate matter closer to the channel. Hence there seems to be a decreasing gradient of particulate organic matter as one goes downstream along the arm.The heterotrophic communities in the arm were fed successively by the decay of autochthonous submerged macrophytes such as Potamogeton in summer and autumn, then by that of terrestrial leaves (mostly alder, poplar and willow with respectively fast, medium and slow processing velocities) and emergent macrophytes such as Phragmites, during winter and spring.A comparison of invertebrate biomass and community structure shows that shredders and collectors are more numerous in winter and spring, white terrestrial leaves are being processed

Examining educators’ conceptualisation of critical thinking in the Algerian higher education context and exploring the challenges faced in promoting critical thinking among students: A qualitative investigation

This thesis addresses two substantial questions, namely: how critical thinking is conceptualised in the Algerian higher education context and to what extent teachers believe they support its development and how they support students’ development of critical thinking in this particular context. The research aims not simply to make an evaluative judgment of the nature of critical thinking, but rather, to capture teachers’ authentic, precise and significant perceptions around critical thinking conceptualisation and development. The research also aims to draw out some significant implications for teaching and learning in the Algerian higher education context which may be pertinent in similar contexts. The research is qualitative in nature adopting an interpretivist approach based on social constructionism that aims to include richness in the perceptions collected and in turn addresses the central research questions. The aim is to comprehend how people perceive, believe, and feel about the world, seeking to understand their different perceptions. Qualitative data was elicited through semi-structured online interviews with 16 teachers at Larbi Ben Mhidi university in Oum El Bouaghi, Algeria. Analysis of the teachers’ perspectives in their answers to the interview questions is presented in a thematic analysis. Overall, it seems that the conceptualisations of critical thinking provided by the interviewed teachers overlap in respect of their provided definitions which understand critical thinking as a set of skill and/ or dispositions. The responses provided by these teachers do also reflect their awareness of the importance of critical thinking and the purposes it could be serving either academically or personally. Key findings emerging from the data analysis show that to develop critical thinking among students, the teachers implemented during their classes different methodologies including classroom discussions, debates, workshops, brainstorming, problem- solving activities, asking questions and lastly self- assessment. However, it the degree to which these teachers supported their students critical thinking is limited as they highlighted different challenges, notably in respect to the context, students, teachers, policy and the social norms. These challenges they believe have significant implications in their support of their students’ critical thinking development. The study is unique in that it provides valuable insights for teachers and researchers in the area of critical thinking conceptualisation and development in higher education, especially for those in Algeria, or in other similar contexts, where graduates are missing such skills. Finally, it is hoped that the current study will inform curriculum designers about future directions and much-anticipated reforms of the Algerian program and practitioners about areas that need to be addressed to further improve the integration of critical thinking into their pedagogical practices