A Multistage Method for SCMA Codebook Design Based on MDS Codes

Sparse Code Multiple Access (SCMA) has been recently proposed for the future generation of wireless communication standards. SCMA system design involves specifying several parameters. In order to simplify the procedure, most works consider a multistage design approach. Two main stages are usually emphasized in these methods: sparse signatures design (equivalently, resource allocation) and codebook design. In this paper, we present a novel SCMA codebook design method. The proposed method considers SCMA codebooks structured with an underlying vector space obtained from classical block codes. In particular, when using maximum distance separable (MDS) codes, our proposed design provides maximum signal-space diversity with a relatively small alphabet. The use of small alphabets also helps to maintain desired properties in the codebooks, such as low peak-to-average power ratio and low-complexity detection.Comment: Submitted to IEEE Wireless Communication Letter

Tertiary Alcohols as Radical Precursors for the Introduction of Tertiary Substituents into Heteroarenes

Despite many recent advances in the radical alkylation of electron-deficient heteroarenes since the seminal reports by Minisci and co-workers, methods for the direct incorporation of tertiary alkyl substituents into nitrogen heteroarenes are limited. This report describes the use of tert-alkyl oxalate salts, derived from tertiary alcohols, to introduce tertiary substituents into a variety of heterocyclic substrates. This reaction has reasonably broad scope, proceeds rapidly under mild conditions, and is initiated by either photochemical or thermal activation. Insights into the underlying mechanism of the higher yielding visible-light initiated process were obtained by flash photolysis studies, whereas computational studies provided insight into the reaction scope

Quantum theory of an atom in proximity to a superconductor

The impact of superconducting correlations on localized electronic states is important for a wide range of experiments in fundamental and applied superconductivity (SC). This includes scanning tunneling microscopy of atomic impurities at the surface of superconductors, as well as superconducting-ion-chip spectroscopy of neutral ions and Rydberg states. Moreover, atom-like centers close to the surface are currently believed to be the main source of noise and decoherence in qubits based on superconducting devices. The proximity effect is known to dress atomic orbitals in Cooper-pair-like states known as Yu-Shiba-Rusinov states (YSR), but the impact of SC on the measured orbital splittings and optical/noise transitions is not known. Here we study the interplay between orbital degenerescence and particle number admixture in atomic states, beyond the usual classical spin approximation. We model the atom as a generalized Anderson model interacting with a conventional $s$-wave superconductor. In the limit of zero on-site Coulomb repulsion ($U=0$), we obtain YSR subgap energy levels that are identical to the ones obtained from the classical spin model. When $\Delta$ is large and $U>0$, the YSR spectra is no longer quasiparticle-like, and the highly degenerate orbital subspaces are split according to their spin, orbital, and number-parity symmetry. We show that $U>0$ activates additional poles in the atomic Green's function, suggesting an alternative explanation for the peak splittings recently observed in scanning tunneling microscopy of orbitally-degenerate impurities in superconductors. We describe optical excitation and absorption of photons by YSR states, showing that many additional optical channels open up in comparison to the non-superconducting case. Conversely, the additional dissipation channels imply increased electromagnetic noise due to impurities in superconducting devices.Comment: 15 pages, 7 figures; corrected typos, updated plot

Comparison of energy consumption and costs of different HEVs and PHEVs in European and American context

This paper will analyse on the one hand the potential of Plug in Hybrid electric Vehicles to significantly reduce fuel consumption and displace it torward various primary energies thanks to the electricity sector. On the other hand the total cost of ownership of two different PHEV architectures will be compared to a conventional cehicle and a HEV without external charging

On the equivalence of the self-dual and Maxwell-Chern-Simons models coupled to Fermions

We study the exact equivalence between the self-dual model minimally coupled with a Dirac field and the Maxwell-Chern-Simons model with non-minimal magnetic coupling to fermions. We show that the fermion sectors of the models are equivalent only if a Thirring like interaction is included. Using functional methods we verify that, up to renormalizations, the equivalence persists at the quantum level.Comment: 8 pages, revte

A comparison between cassava starch production at small-scale in Vietnam and in Colombia

In Colombia and in Vietnam, small-scale cassava starch processing is conducted at similar scales but with contrasted extraction technologies. Based on the methodology of diagnosis previously applied in Vietnam, two set of trials with two different cassava cultivars (var. mper183 and var. algodona) were carried out in a typical processing plant from Northern Cauca in Colombia. Moisture, starch, crude fibres and ash content analysis were carried out on samples collected from the manufacturing process to establish the mass balance of starch. Production capacity, water consumption, electrical requirements and capital-labor costs per tonne of starch (12% moisture) were also reported. The manufacturing process enabled 65% recovery of the starch present in fresh roots, with no significant change observed in the composition of starch for the two varieties. The bottleneck of the manufacturing process occurred at extraction stage were low capacity were observed (0.3 t of peeled roots per hour). Water consumption per ton of starch was 67 m3, in which washing, rasping, and extraction stages accounted for 9, 3, and 42 m3, respectively. Electrical power per tone of starch was 59 kWh, in which, washing, rasping, and extraction stages accounted for 8, 14 and 38 kWh. The comparison proposed in this study allowed to recommend technological options for small-scale cassava processing industries. (Résumé d'auteur

Physicochemical and Functional characteristics of tropical starches from Vietnam and Thailand: Granule size, thermal properties and viscosity

This study attempts at exploring the physicochemical and functional characteristics of several types of tropical starches separated from starch-producing plants from South-East Asia. In Vietnam and Thailand, despite the fact that starch is the major component of tubers, these crops remain underutilized and represent a potential field for post-harvest applications. In this work, selected root and tuber crops were potato, sweet potato, cassava, taro, yam bean and canna. Sago was the tree crop sample; kudzu and mung bean as legumes samples. Common cereals like rice and maize were also selected as references. Granule size was measured by laser diffraction. Thermal properties were obtained by DSC analysis. Viscosity properties were determined by RVA. The results obtained with cereals, legumes and other types of starches, were contrasted, suggesting a separate analysis of starches from root and tubers. The selected root and tuber starches had lipid, protein and ash contents in the range of 0.16-0.52%, 0.08-0.21% and 0.01-0.44% respectively. Significant differences in the granule size distribution between starches were observed with the largest type of granules for canna (55^m). DSC gelatinization temperatures were lower for cassava than for aroids. Further investigations are needed to better understand the relationships between proximate analysis, granule distribution and thermal properties of starches, thus the quality of the foodstuffs manufactured from root and tuber crops. (Texte intégral

Analyse de la structure des haies dans les vergers pour la définition de paysages mieux adaptés contre les bioagresseurs

National audienceAfin de modéliser la structure des haies de vergers, nous utilisons des méthodes de fouille de données. Ainsi, les chaînes de Markov couplées avec les chemins de Hilbert-Peano et les processus ponctuels servent à déterminer les paramètres propres à la disposition des haies dans le paysage. Ceci permet, par la suite, de simuler des paysages valides afin de créer des scénarios paysagers luttant contre les ravageur

Avec Orima - Designing the brand identity

The thesis is a document in building the brand image for the authors’ own start-up Avec Orima. It is motivated by the need to take the company from the planning stage to the next very first step of implementing the business – designing the company’s brand identity. The thesis focused on the process of designing the brand identity. The process began with analysing the company and Finnish target market to have the insights on what the company stands for and wants to achieve. The study then continued to examine the competition in Finnish market and identify the points of differences, in order to establish the brand positioning. Upon understanding the Avec Orima brand and what it stands for, the thesis study integrated the brand identity strategy with design skills to create the basic elements of Avec Orima’s visual brand identity – logotype, typography, colours, look and feel, and imagery. Using a sample of 57 people, the authors collected data from a survey. Also, data from market research was presented. As predicted, the results justify the authors’ points on the existing behaviours, trends and rising demands in Finnish market. The authors conclude that, despite a limitation in existing customer behaviours at the moment, there are rising awareness and demand for such a service provider like Avec Orima. This conclusion is the foundation for all further studies, which are based on theoretical data, in defining the company, then brand positioning and brand identity design