On Even Length Codes Over Finite Rings

Codes over finite rings have been studied in the early 1970. A great deal of attention has been given to codes over finite rings from 1990, because of their new role in algebraic coding theory and their successful application. The key to describing the structure of cyclic codes over a ring R is to view cyclic codes as ideals in the polynomial ring R[x]/, where n is the length of the code. In previous studies, some authors determined the structure of cyclic codes over Z4 for arbitrary even length by finding the generator polynomial, the number of cyclic codes for a given length and the duals for these codes, and also determined the structure of negacyclic codes of even length over the ring Z2a and their dual codes. In this thesis, we introduce cyclic codes of an arbitrary length n over the rings F2 + uF2 with u2 = 0 mod 2 and F2 + uF2 + u2F2 with u3 = 0 mod 2. We find a set of generators for these codes. The rank and the dual of these codes are studied as well. We will extend these results about the rings F2 +uF2 and F2 +uF2 +u2F2 to more general rings F2 + uF2 + u2F2 = : : : + uk-1F2 with uk = 0 mod 2. Finally we study the structure of (1 + u)-constacyclic codes of even length n over the ring F2 + uF2 with u2 = 0 mod 2. Also we extend this study to the ring F2 + uF2 + u2F2 with u3 = 0 mod 2

Optimal Pricing and order quantity strategies for a firm offering multiple products facing customers cannibalization and random market demand

This paper studies a firm’s profitability problem offering its products into different market segments at differentiated prices. In order to improve the firms’ profitability the firm needs to decide the prices and order quantities allocations for each market segment. In perfect market segmentation, it is assumed that the customers do not cannibalize between market segments. Whereas, in the case of imperfect market segmentation, the customers are assumed to cannibalize from a high price market segment to a lower price segment. Models to determine the optimal strategies for pricing and order quantity for the perfect as well as for the imperfect market segmentations are proposed with both the deterministic and stochastic customers’ demand. The study has shown that the perfect market segmentation always yields higher revenues compared to no segmentation for a firm facing both the deterministic and stochastic demand situations. In addition to this, the study has also shown that when cannibalization exists, a firm is still able to yield higher revenues compared to the case of no market segmentation facing both the deterministic and stochastic demands, however, greater the extent of cannibalization could result substantial losses in the profitability

Engineering polymer informatics: Towards the computer-aided design of polymers

The computer-aided design of polymers is one of the holy grails of modern chemical informatics and of significant interest for a number of communities in polymer science. The paper outlines a vision for the in silico design of polymers and presents an information model for polymers based on modern semantic web technologies, thus laying the foundations for achieving the vision

New Future Ring Layout with Parallel Boreholes : Results from Small - Scale Blasting Tests

Validerat; 20130506 (global_studentproject_submitter

Développement de systèmes particulaires magnétiques et radioactifs pour le traitement anti-tumoral par la technique TMT (Targeted MultiTherapy)

Ce travail de thèse a été effectué dans le cadre d une collaboration du laboratoire LAGEP dans le projet INBARCA, un projet de recherche européen. L objectif de ce travail a été d élaborer et de caractériser des systèmes particulaires adaptés à l administration intratumorale par la technique TMT. Trois types de ces systèmes ont été préparés par la méthode d émulsification-évaporation de solvant avec succès. Ces systèmes comprennent; d abord, des particules superparamagnétiques permettant un suivi de la distribution intratumorale via l imagerie par résonance magnétique (IRM). Deuxièmement, des nanoparticules à visée radiothérapeutique, chargées en rhénium-185, rhénium-187 ou holmium-165 pour une activation neutronique via soit des réacteurs nucléaires ou des cyclotrons dans une étape plus lointaine. Enfin, des microparticules chargées en paclitaxel, pour une chimiothérapie localisée permettant de sensibiliser les cellules cancéreuses à la radiothérapie effectuée par les nanoparticules radioactives dans une étape ultérieureThis work was carried out in the framework of LAGEP laboratory s collaboration in the project INBARCA, a European research project. The objective of this work was to prepare and characterize particulate systems adapted to the intra-tumoral administration by the TMT technique. Three types of these systems were successfully prepared by the method of emulsification-solvent evaporation. These systems include; firstly, superparamagnetic particles allowing to track the intra-tumoral distribution via magnetic resonance imaging (MRI). Secondly, nanoparticules for a radiotherapeutic application, loaded with rhenium-185, rhenium-187 or holmium-165 for neutron activation via nuclear reactors or cyclotrons in a future stage. Thirdly, microparticles loaded with paclitaxel, for a localized chemotherapy allowing the sensitization of cancerous cells toward radiotherapy which would be carried out by the radioactive nanoparticules in a subsequent stepLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Positive contrast with therapeutic iron nanoparticles at 4.7 T

OBJECT: The purpose of the study was to show the feasibility of a positive contrast technique GRadient echo Acquisition for Superparamagnetic particles with Positive contrast (GRASP), for a specific type of magnetic particles, designed for tumor treatment under MRI monitoring. MATERIALS AND METHODS: A simulation study was performed to estimate field inhomogeneity intensities induced by increasing concentrations of particles at different static fields. The GRASP sequence was setup on a 4.7 T Bruker system during an in vitro study. Six mice, included in the in vivo study received particles in the left calf muscle and contrast enhancement values, were measured over three time points, for both negative and positive contrast images. RESULTS: Comparing values obtained by simulation at 1.5, 3, and 4.7 T, the strongest susceptibility effect was obtained at 4.7 T. Based on simulation and in vitro data, gradient settings were chosen for in vivo imaging. GRASP resulted in bright regions at and around the injection site, and higher enhancement values, compared to standard GRE imaging. Both contrasts were useful for longitudinal follow-up, with a faster decay over time for GRASP. CONCLUSION: The magnetic nanoparticles for drug delivery can be detected using positive contrast. Combining imaging sequences, i.e., negative contrast and susceptibility methods, increased imaging specificity of large magnetic particles and enabled their follow-up for theranostic applications

Cyclic codes over {Z_2+ uZ_2+ u^ 2Z_2+\ldots+ u^{k-1} Z_2}

In this paper, we study the structure of cyclic codes of an arbitrary length n over the ring Z_2+ uZ_2+ u^ 2Z_2+\ldots+ u^{k-1} Z_2, where u^ k= 0. Also we study the rank for these codes, and we find their minimal spanning sets. This study is a generalization and extension of the work in reference [1]