201 research outputs found
Quantum Computing Assisted Medium Access Control for Multiple Client Station Networks
A medium access control protocol based on quantum entanglement has been
introduced by Berces and Imre (2006) and Van Meter (2012). This protocol
entirely avoids collisions. It is assumed that the network consists of one
access point and two client stations. We extend this scheme to a network with
an arbitrary number of client stations. We propose three approaches, namely,
the qubit distribution, transmit first election and temporal ordering
protocols. The qubit distribution protocol leverages the concepts of Bell-EPR
pair or W state triad. It works for networks of up to four CSs. With up to
three CSs, there is no probability of collision. In a four-CS network, there is
a low probability of collision. The transmit first election protocol and
temporal ordering protocols work for a network with any number of CSs. The
transmit first election builds upon the concept of W state of size
corresponding to the number of client stations. It is fair and collision free.
The temporal ordering protocol employs the concepts of Lehmer code and quantum
oracle. It is collision free, has a normalized throughput of 100% and achieves
quasi-fairness.Comment: 18 pages, 12 figures, 3 tables; manuscript under revie
Substrat glaciotectonisé et till syngénétique à Pont-Rouge, Québec
GrĂące Ă un effondrement Ă l'aplomb d'une galerie souterraine qui recoupe un mĂ©andre de la riviĂšre Jacques-Cartier Ă Pont-Rouge, des calcaires fortement glaciotectonisĂ©s ont pu ĂȘtre observĂ©s. Toutes les perturbations d'origine glaciaire de l'encaissant y sont relevĂ©es pour la premiĂšre fois en un mĂȘme site. Elles sont remarquablement conservĂ©es par un till de fond Ă©pais de prĂšs de 10 m. Sur Ă peine 40 m de distance on observe : un plan de diaclase en contact avec un till, des plans de stratification dĂ©collĂ©s et rebroussĂ©s par du till, un pli-faille partiellement coffrĂ© dont le coeur et le plan de chevauchement contiennent du till, un plan de chevauchement servant de « faille de rampe » pour des copeaux submĂ©triques de calcaire, des fissures ouvertes injectĂ©es de till et ayant subi une rotation vers la droite de 25°. Enfin Ă l'interface entre le calcaire glaciotectonisĂ© et celui en place, on trouve des stries glaciaires avec polaritĂ© ouest-est. Nous pensons que c'est au plus tard au maximum glaciaire du Wisconsinien supĂ©rieur que se situerait leur apparition. Advenant la confirmation de cette hypothĂšse, il faudrait alors en conclure que la calotte glaciaire laurentidienne, Ă cette Ă©poque et localement, s'Ă©coulait vers l'est.Ice-push forms have been noted in highly deformed limestone beds at the base of a collapse sinkhole which has formed right over a 170 m underground inlet tunnel bypassing a meander of the RiviĂšre Jacques-Cartier. Nowhere had all types of ice-push structures been identified in a single outcrop. These have been remarkably preserved by a 10 m thick lodgement till. In only 40 m along this outcrop one is able to recognize the following structures: 1) a vertical joint plane in close contact with the till; 2) turned over and folded bedding planes surrounded by till; 3) a faulted concentric fold with core and thrust-plane filled with till; 4) a thrust plane used as a "rising fault'' by submetric limestone blocks; 5) opened vertical joints filled with till and rotated clockwise by some 25e. Eastward glacial striae have also been observed between the undisturbed massive limestone and the deformed ones. We think that these ice-push structures have been generated during the Late Wisconsinan glacial maximum at the latest. If this hypothesis is confirmed, one would have to conclude that, during this time lapse and location, the Laurentide Ice Sheet was flowing eastward.Dank eines Einsturzes senkrecht uber einem unterirdischen Stollen, der eine Schleife des Jacques-Cartier-Flusses bei Pont-Rouge durchschneidet, konnten stark glaziotektonisierte Kalksteine beobachtet werden. AIIe Storungen glazialen Ursprungs des Einschnittes sind dort zum ersten Mal an einem einzigen Fundplatz vereinigt. Durch ein Grund-Till von fast 10 m Dicke sind sie ausserordentlich gut erhalten. Auf kaum 40 m Entfernung beobachtet man : Eine Ebene von Fugen in Kontakt mit einem Till, geschichtete FlĂ chen die durch Till abgelĂŽst und umgekehrt worden sind, eine Bruchfalte und teilweise Kofferfalte, deren Kern und Scheerebene Till enthalten, eine Scheerebene, die als ansteigender Bruch fur submetrische KaIksteinspĂ ne dient, offene mit Till angefĂčllte Risse, die eine Rotation nach rechts urn 25" durchgemacht haben. Schliesslich findet man zwischen dem glaziotektonisierten Kalkstein und dem vorhandenen glaziale Schrammen in West-Ost-Richtung. Wir denken, dass sie spĂ testens im glazialen Maximum des spĂ ten Wiskonsinium aufgetreten sind. Sollte diese HypothĂšse sich bestĂątigen, mĂčsste man folgern, dass das laurentidische Inlandeis damais und ĂŽrtlich in Richtung Osten abfloss
Conception dâun guide pour accompagner la ou le spĂ©cialiste de contenu en contexte de formation manquante en RAC au collĂ©gial
Cet essai porte sur la conception dâun guide pour accompagner la ou le spĂ©cialiste de contenu dans un contexte de formation manquante dans le cadre de la reconnaissance des acquis et des compĂ©tences (RAC) au collĂ©gial. LâĂ©tape de la formation manquante, dĂ©crite dans le Cadre gĂ©nĂ©ral-Cadre technique (Gouvernement du QuĂ©bec, 2005) et qui permet de dĂ©finir la RAC au secondaire et au collĂ©gial, consiste Ă fournir Ă la personne candidate les ressources nĂ©cessaires qui lâaideront Ă mobiliser les Ă©lĂ©ments dâune compĂ©tence requis, afin de rĂ©pondre aux Ă©valuations Ă des fins de diplomation dans un programme de formation donnĂ©. Les donnĂ©es recensĂ©es par le ministĂšre responsable lâĂ©ducation et de lâenseignement supĂ©rieur indiquent quâĂ la fin du processus dâĂ©valuation en RAC, le recours Ă la formation manquante fait partie des services de plus en plus utilisĂ©s. Toutefois, pour offrir le service de RAC, les collĂšges doivent recruter du personnel qualifiĂ© qui Ă©valuera les personnes candidates conformĂ©ment aux compĂ©tences du programme dans lequel ces personnes sont inscrites. Un rĂ©fĂ©rentiel de compĂ©tences rĂ©cemment mis en place dĂ©crit les compĂ©tences souhaitĂ©es du spĂ©cialiste de contenu dont une concerne lâaccompagnement auprĂšs de la personne candidate (Groupe de travail CERAC, 2014). Le chercheur sâest inspirĂ© de ce rĂ©fĂ©rentiel de compĂ©tences pour questionner les ressources Ă la disposition du spĂ©cialiste de contenu pour lâaider dans sa tĂąche Ă lâĂ©tape de la formation manquante. Câest en lâabsence de matĂ©riel spĂ©cifique Ă cet effet que le problĂšme de recherche sâest imposĂ© justifiant la question suivante : Comment rĂ©soudre le manque dâoutils pour accompagner la ou le spĂ©cialiste de contenu qui intervient en RAC au collĂ©gial dans un contexte de formation manquante? Or, lâaccompagnement requiert un minimum de connaissances, dâhabiletĂ©s et de compĂ©tences chez la ou le spĂ©cialiste de contenu. Cette question de recherche amĂšne Ă considĂ©rer trois concepts dĂ©jĂ explorĂ©s par des chercheures et chercheurs pour constituer notre cadre de rĂ©fĂ©rence et qui ont Ă©clairĂ© notre problĂ©matique. Il sâagit des concepts de compĂ©tence, dâandragogie et dâaccompagnement qui ont menĂ© Ă la dĂ©termination de lâobjectif spĂ©cifique de recherche : Concevoir un guide pour soutenir la ou le spĂ©cialiste de contenu Ă accompagner efficacement la personne candidate Ă lâĂ©tape de la formation manquante en RAC au collĂ©gial. Lâapproche mĂ©thodologique qualitative utilisĂ©e pour atteindre lâobjectif de recherche tient compte des Ă©tapes de production de matĂ©riel pĂ©dagogique du devis de PaillĂ© (2007) soit la planification, lâĂ©laboration et la validation dâun matĂ©riel pĂ©dagogique. Pour que ce nouveau matĂ©riel soit reconnu pertinent par la ou le spĂ©cialiste de contenu, lâĂ©tape de validation sâest effectuĂ©e auprĂšs dâun groupe de spĂ©cialistes de contenu, ayant une expĂ©rience professionnelle variĂ©e et provenant de domaines disciplinaires diffĂ©rents. Le chercheur a utilisĂ© trois modalitĂ©s de collecte de donnĂ©es, soit le questionnaire Ă©lectronique, le groupe dâentretien et le journal de bord. Les rĂ©sultats de la recherche ont dĂ©montrĂ© que les spĂ©cialistes de contenu ayant participĂ© Ă la validation du guide considĂšrent que la structure organisationnelle du matĂ©riel pĂ©dagogique et sa forme sont efficaces, pertinentes et utiles. LâutilitĂ©, la clartĂ© et la quantitĂ© dâinformations ainsi que le dĂ©coupage et le dĂ©veloppement des idĂ©es sont notamment trĂšs apprĂ©ciĂ©s. Dâailleurs, les spĂ©cialistes de contenu ayant validĂ© le guide affirment unanimement quâil rĂ©pond Ă un besoin de ressources pour accompagner la personne candidate Ă lâĂ©tape de la formation manquante
Condensation d'ADN plasmidique par des diamines sur un substrat de graphite HOPG
National audienceCe travail vise Ă amĂ©liorer notre connaissance des effets produits par les Ă©lectrons de basse Ă©nergie (EBEs) sur l'ADN. Parmi les composants radiosensibles, les acides nuclĂ©iques demeurent en effet une cible critique des EBEs. Ce type d'Ă©tude requiert un bon Ă©talement et un contrĂŽle des dĂ©pĂŽts d'ADN plasmidique sur des surfaces conductrices. Nous avons Ă©tudiĂ© en dĂ©tails la formation de complexes entre des polyamines et l'ADN plasmidique. Une partie du travail a consistĂ© Ă caractĂ©riser les dĂ©pĂŽts rĂ©alisĂ©s sur des substrats de graphite pyrolytique hautement orientĂ© (HOPG) en employant des diamines pour condenser l'ADN. Nous avons montrĂ© que dans les conditions opĂ©ratoires de cette Ă©tude, il est possible de crĂ©er des dĂ©pĂŽts avec des Ă©paisseurs calibrĂ©es, prĂ©sentant un taux dĂ©gĂąts constant et suffisamment bas pour permettre des Ă©tudes ultĂ©rieures en gel d'Ă©lectrophorĂšse. Ces dĂ©pĂŽts, dont l'Ă©paisseur varie de deux Ă plusieurs dizaines de nanomĂštres, ont la propriĂ©tĂ© remarquable de pouvoir ĂȘtre re-dissous dans l'eau sans qu'ils ne subissent de dommages supplĂ©mentaires. Les dĂ©pĂŽts rĂ©alisĂ©s avec le diaminopropane ont Ă©tĂ© exposĂ©s aux EBEs et une premiĂšre exploitation par dĂ©sorption stimulĂ©e (ESD) et par relaxation de plasmide a Ă©tĂ© effectuĂ©e. Ces premiers rĂ©sultats ouvrent de larges perspectives pour l'utilisation ultĂ©rieure des dĂ©pĂŽts crĂ©Ă©s durant ce travail
Dissociative electron attachment to DNA-diamine thin films: Impact of the DNA close environment on the OH(-) and O(-) decay channels.
International audience: We measure the desorption of anions stimulated by the impact of 0-20 eV electrons on highly uniform thin films of plasmid DNA-diaminopropane. The results are accurately correlated with film thickness and composition by AFM and XPS measurements, respectively. Resonant structures in the H(-), O(-), and OH(-) yield functions are attributed to the decay of transient anions into the dissociative electron attachment (DEA) channel. The diamine induces ammonium-phosphate bridges along the DNA backbone, which suppresses the DEA O(-) channel and in counter-part increases considerably the desorption of OH(-). The close environment of the phosphate groups may therefore play an important role in modulating the rate and type of DNA damages induced by low energy electrons
Brief communication: On direct impact probability of landslides on vehicles
Abstract. When calculating the risk of railway or road users of being killed by a natural hazard, one has to calculate a temporal spatial probability, i.e. the probability of a vehicle being in the path of the falling mass when the mass falls, or the expected number of affected vehicles in case such of an event. To calculate this, different methods are used in the literature, and, most of the time, they consider only the dimensions of the falling mass or the dimensions of the vehicles. Some authors do however consider both dimensions at the same time, and the use of their approach is recommended. Finally, a method considering an impact on the front of the vehicle is discussed
Absolute cross section for loss of supercoiled topology induced by 10 eV electrons in highly uniform âDNAâ1,3-diaminopropane films deposited on highly ordered pyrolitic graphite.
International audience: It was recently shown that the affinity of doubly charged, 1-3 diaminopropane (Dap(2+)) for DNA permits the growth on highly ordered pyrolitic graphite (HOPG) substrates, of plasmid DNA films, of known uniform thickness [O. Boulanouar, A. Khatyr, G. Herlem, F. Palmino, L. Sanche, and M. Fromm, J. Phys. Chem. C 115, 21291-21298 (2011)]. Post-irradiation analysis by electrophoresis of such targets confirms that electron impact at 10 eV produces a maximum in the yield of single strand breaks that can be associated with the formation of a DNA(-) transient anion. Using a well-adapted deterministic survival model for the variation of electron damage with fluence and film thickness, we have determined an absolute cross section for strand-break damage by 10 eV electrons and inelastic scattering attenuation length in DNA-Dap complex films
Development of a long term monitoring network of sensitive clay slopes in Québec in the context of climate change
The Government of Québec recently initiated the deployment of a vast
groundwater pressures monitoring network in postglacial marine clays to document
their variations in time and improve our understanding of the relationship between
failure initiation and climate in clay slopes. This project aims at evaluating the
impacts of climate change on clay-slope stability and how it can be integrated
in landslide risk management to improve public safety. Hydrogeological data
will be acquired at sites located throughout the QuĂ©bec Provinceâs post-glacial
clay deposits to create a public georeferenced index of typical hydrogeological
conditions. The project goes beyond the characterization of groundwater pressures
and their variations in clay slopes. Indeed, slope deformation will be measured at
several sites. Also, two sites in flat terrain will be instrumented in order to evaluate
mechanical properties of clay layers in simple 1-D conditions and groundwater
recharge. The unsaturated clay crust in slopes susceptible to superficial landslides
will be characterized and instrumented. The current lifetime of the monitoring
project has been set to a period of 25 years.
Hydrogeology of a complex Champlain Sea deposit (Quebec, Canada) : implications for slope stability
The thick sequences of marine clayey deposits which blanket the St. Lawrence Lowlands in south-eastern Canada are highly susceptible to landslides. With 89% of the population of the Province of Quebec living in this region, improving our understanding of the mechanisms causing landslides in these sediments is a matter of public security. To accomplish this goal, instruments were deployed at a field site in Sainte-Anne-de-la-PĂ©rade, Quebec, Canada to monitor atmospheric, soil, and groundwater conditions. Field and laboratory measurements of soil geotechnical and hydraulic properties were also performed. Results indicate that the groundwater and pore pressure dynamics at the site cannot be explained using simplified site conceptual models. Further analysis indicates that groundwater dynamics and pore pressures in the massive clay deposits on-site are determined by (i) the highly-heterogeneous nature of the local geological materials (ii) the contrasting hydraulic and geotechnical properties of these materials, (iii) the presence of two unconfined aquifers at the site, one surficial and one at depth, and (iv), the presence of the Sainte-Anne River. These results were used to create a new conceptual model which illustrates the complex groundwater flow system present on site, and shows the importance of including hydrogeologic context in slope stability analysis
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