Efficient Heuristic for Resource Allocation in Zero-forcing OFDMA-SDMA Systems with Minimum Rate Constraints

4G wireless access systems require high spectral efficiency to support the ever increasing number of users and data rates for real time applications. Multi-antenna OFDM-SDMA systems can provide the required high spectral efficiency and dynamic usage of the channel, but the resource allocation process becomes extremely complex because of the augmented degrees of freedom. In this paper, we propose two heuristics to solve the resource allocation problem that have very low computational complexity and give performances not far from the optimal. The proposed heuristics select a set of users for each subchannel, but contrary to the reported methods that solve the throughput maximization problem, our heuristics consider the set of real-time (RT) users to ensure that their minimum rate requirements are met. We compare the heuristics' performance against an upper bound and other methods proposed in the literature and find that they give a somewhat lower performance, but support a wider range of minimum rates while reducing the computational complexity. The gap between the objective achieved by the heuristics and the upper bound is not large. In our experiments this gap is 10.7% averaging over all performed numerical evaluations for all system configurations. The increase in the range of the supported minimum rates when compared with a method reported in the literature is 14.6% on average.Comment: 8 figure

An Object of Discourse for Studies of Pornography

Pornography has been the subject of much recent discussion, particularly in France. It has become an everyday theme in media discourse as the numerous articles, special files and columns in the printed and online press demonstrate, as does the multiplication of "sex" features under various names in nearly all the French daily and weekly papers, on numerous radio stations and television channels. Pornography has also become a research subject and is now an integral part of humanities and socia..

Éléments du pathos pornographique

Le travail présenté dans la contribution repose sur l’observation de dialogues dans des séquences pornographiques diffusées sur des sites portails du web communément appelés tubes. Après avoir présenté de manière générale les productions langagières présentes dans ces extraits vidéographiques, elle se concentre sur les manifestations vocales et verbales de l’émotion, leurs liens dans la distribution des rôles actanciels et interactionnels (procurant/procuré) et leur rôle dans la mise en scène de la vraisemblance des affects. Pour finir, elle revient sur les éléments de l’énonciation pathémique des personnages et l’entreprise de captation du spectateur.The presented work is based on the observation of dialogues in pornographic sequences broadcast on web portals commonly known as tubes. After presenting the productions observed in these extracts, it focuses on vocal and verbal manifestations of emotion, their links in the distribution of actant and interactional roles (providing / provided) and their role in the staging of the likelihood of affects. Finally, it discusses the elements of the pathemic enunciation of the characters and the attempt to capture the viewer

Nature et domotique du langage : Une approche des interactions naturelles homme-machine en environnement pervasif

L’évolution industrielle nous destine à vivre dans des environnements technologiques caractérisés par une dissémination informatique totale dans la multitude et d’objets connectés capables de traitement sémantique et d’interaction informationnelle avec les humains. Dans ce contexte d’Intelligence ambiante (Zelkha et al., 1998) se déploient des dispositifs domotiques d’Interactions dites naturelles Homme / machine. Ainsi de Google Home (dont la présentation en ligne par la firme sert de corpus pour le présent travail) présenté comme : « une enceinte à commande vocale qui fonctionne avec l'Assistant Google » (https://madeby.google.com/home/, consulté le 04/10/2017). On pourra tout aussi bien discuter avec les agents de la concurrence : Amazon Echo, Apple HomePod, etc. Ces dispositifs nous conduisent à interroger une étape contemporaine majeure de « la révolution technologique du langage » (Auroux, 1994) et de son automatisation (Léon, 2015), qui fait des machines de réels sujets parlants, inscrits dans un « couplage humano-machinique » (Sadin, 2013). Dans ce contexte fortement marqué par les affordances (Gibson, 1977), nous observons les modalités de cette interaction artéfactuelle et dite naturelle, caractérisée notamment par une simulation conversationnelle et une personnalisation des dispositifs technologiques. La perspective est celle d’une linguistique post-dualiste et non logocentrée, dans la lignée du courant de l’analyse du discours (en interaction) : Texte-Discours-Interaction (Paveau, 2012).Nowadays, our technological environment is characterized by a total computer dissemination in the intelligent and connected objects. In this context of Ambient Intelligence (Zelkha et al., 1998) the domotic devices are deployed in so-called '' natural'' interactions with humans. For example Google Home is presented as: "a voice-activated speaker that works with the Google Assistant" (https://madeby.google.com/home /, accessed 04/10/2017). We can also discuss with the competition agents: Amazon Echo, Apple HomePod, etc. These devices lead us to question a new step of "the technological revolution of language" (Auroux, 1994) and its automation (Léon, 2015), which makes machines real talking subjects, enrolled in a "human-machine coupling" "(Sadin, 2013). In this context of affordances (Gibson, 1977), we observe the modalities of the H/M interaction, characterized in particular by a conversational simulation and a personalization of the technological devices. Our perspective is post-dualistic and non-logocentric, in line with the current of discourse analysis (in interaction): Text-Speech-Interaction (Paveau, 2012)

Un objet de discours pour les études pornographiques

La pornographie fait beaucoup parler d’elle ces derniers temps, en France en particulier : d’une part, elle est devenue un thème ordinaire dans les discours médiatiques, comme en témoignent de nombreux articles, dossiers et billets dans la presse papier et en ligne, ainsi que la multiplication des rubriques « sexe » (sous des appellations diverses, dans quasiment tous les quotidiens et hebdomadaires français, et de nombreuses radios et chaînes de télévision) ; d’autre part, elle est devenue u..

Dual-based bounds for resource allocation in zero-forcing beamforming OFDMA-SDMA systems

We consider multi-antenna base stations using orthogonal frequency-division multiple access and space division multiple access techniques to serve single-antenna users. Some users, called real-time users, have minimum rate requirements and must be served in the current time slot while others, called non real-time users, do not have strict timing constraints and are served on a best-effort basis. The resource allocation (RA) problem is to find the assignment of users to subcarriers and the transmit beamforming vectors that maximize the total user rates subject to power and minimum rate constraints. In general, this is a nonlinear and non-convex program and the zero-forcing technique used here makes it integer as well, exact optimal solutions cannot be computed in reasonable time for realistic cases. For this reason, we present a technique to compute both upper and lower bounds and show that these are quite close for some realistic cases. First, we formulate the dual problem whose optimum provides an upper bound to all feasible solutions. We then use a simple method to get a primal-feasible point starting from the dual optimal solution, which is a lower bound on the primal optimal solution. Numerical results for several cases show that the two bounds are close so that the dual method can be used to benchmark any heuristic used to solve this problem. As an example, we provide numerical results showing the performance gap of the well-known weight adjustment method and show that there is considerable room for improvement

Exhaust gas recirculation dispersion analysis using in-cylinder pressure measurements in automotive diesel engines

Current diesel engines are struggling to achieve exhaust emissions regulations margins, in certain cases penalizing the fuel consumption. The exhaust gas recirculation (EGR) continues to be employed as a technique to reduce NOx emissions. EGR dispersion between cylinders is one important issue when a high pressure (HP) loop is used. Different techniques have been developed in order to analyze the EGR dispersion between cylinders in an engine test bench. In this paper a methodology using the in-cylinder pressure was developed. The in-cylinder pressure was used to calculate a heat release law and combustion parameters that were used to analyze the EGR dispersion between cylinders. Engine test measurements at three different engine speeds and with three different HP-EGR configurations were performed in order to assess the developed analysis methodology. NOx emissions and fuel consumption were also compared between the different HP-EGR configurations to complete the analysis. The developed methodology was successfully used in three different operating conditions for three different HP-EGR configurations, showing the relation between the decrease in EGR dispersion between cylinders and the decrease in NOx emissions, while maintaining and, in some points, improving the fuel consumption.Luján, JM.; Climent, H.; Pla Moreno, B.; Rivas Perea, ME.; Francois, N.; Borges Alejo, J.; Soukeur, Z. (2015). Exhaust gas recirculation dispersion analysis using in-cylinder pressure measurements in automotive diesel engines. Applied Thermal Engineering. 89:459-468. doi:10.1016/j.applthermaleng.2015.06.029S4594688

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives