INFO2009 2012-13 Resource Group 6 Flashcards

An inspirational and educational flashcard resource for secondary school children. Can be used as flashcards or as a matching activity (depending on how cards are cut out).

Institutions & Their Data

A panel presentation at Repository Fringe 2015

Att överföra geospatiala data från en relationsdatabas till densemantiska webben

Semantiska webben är ett begrepp som handlar om att göra data tillgängligt på ett sätt som gör att datorer kan söka, tolka och sätta data i ett sammanhang. Då mycket av datalagring idag sker i relationsdatabaser behövs nya sätt att omvandla och lagra data för att det ska vara tillgängligt för den semantiska webben.Forskning som genomförts har visat att transformering av data från relationsdatabaser till RDF som är det format som gör data sökbart på semantiska webben är möjlig men det finns idag ingen standardisering för hur detta ska ske.För att data som transformeras ska få rätt betydelse i RDF så krävs ontologier som beskriver olika begrepps relationer. Nationella vägdatabasen (NVDB) är en relationsdatabas som hantera geospatiala data som används i olika geografiska informationssystem (GIS). För samarbetspartnern Triona var det intressant att beskriva hur denna typ av data kan omvandlas för att passa den semantiska webben.Syftet var att analysera hur man överför geospatiala data från en relationsdatabas till den semantiska webben. Målet med studien var att skapa en modell för hur man överför geospatiala data till i en relationsdatabas till en RDF-lagring och hur man skapar en ontologi som passar för NVDB’s data och datastruktur.En fallstudie genomfördes med dokumentstudier utifrån en inledande litteraturstudie.En ontologi skapades för det specifika fallet och utifrån detta skapades en modell för hur man överför geospatiala data från NVDB till RDF via programvaran TripleGeo. Analysen har skett genom att transformerad data har analyserats med hjälp av befintlig teori om RDF och dess struktur och sedan jämföra och se så att data får rätt betydelse. Resultatet har också validerats genom att använda W3C’s tjänst för att validera RDF.Resultatet visar hur man transformerar data från en relationsdatabas med geospatiala data till RDF samt hur en ontologi för detta skapats. Resultatet visar också en modell som beskriver hur detta utförs och kan ses som ett försök till att generalisera och standardisera en metod för att överföra geospatiala data till RDF.

Semantic Enrichment of Scientific Documents with Semantic Lenses – Developing methodologies, tools and prototypes for their concrete use

Con questa dissertazione di tesi miro ad illustrare i risultati della mia ricerca nel campo del Semantic Publishing, consistenti nello sviluppo di un insieme di metodologie, strumenti e prototipi, uniti allo studio di un caso d‟uso concreto, finalizzati all‟applicazione ed alla focalizzazione di Lenti Semantiche (Semantic Lenses).

Modelli per l'aggregazione di dati federati: il caso degli orari di apertura degli esercizi commerciali e enti pubblici

Questa tesi tratta di scambio di dati aperti (open data exchange). In particolare, tratta di intervalli temporali con annesse informazioni di vario tipo. Le attività commerciali, come aziende, bar, ristoranti, cinema, teatri, e via dicendo, hanno bisogno di un modo comune per poter condividere i dati inerenti ai propri orari (timetable). Lo scopo di questa tesi è quello di mostrare un modello efficiente, compatto e completo per poter condividere tali informazioni con l'ausilio di formati standard (XML). Oggi giorno esistono diverse soluzioni atte a far fronte a questa necessità ma si tratta di soluzioni incomplete e che gestiscono tali informazioni separatamente. Il problema sorto è quello di avere un'unica struttura che posso unificare informazioni di diverso carattere con gli orari di un'attività: un cinema ha la necessità di fornire orari di diverse proiezioni svolte in sale diverse, una tournée dovrà poter specificare le coordinate geografiche del prossimo evento e così discorrendo.

Data analysis and simulations of VIRTIS venus spectra

VIRTIS, a bordo di Venus Express, è uno spettrometro in grado di operare da 0.25 a 5 µm. Nel periodo 2006-2011 ha ricavato un'enorme mole di dati ma a tutt'oggi le osservazioni al lembo sono poco utilizzate per lo studio delle nubi e delle hazes, specialmente di notte. Gli spettri al lembo a quote mesosferiche sono dominati dalla radianza proveniente dalle nubi e scatterata in direzione dello strumento dalle hazes. L'interpretazione degli spettri al lembo non può quindi prescindere dalla caratterizzazione dell'intera colonna atmosferica. L'obiettivo della tesi è di effettuare un’analisi statistica sulle osservazioni al nadir e proporre una metodologia per ricavare una caratterizzazione delle hazes combinando osservazioni al nadir e al lembo. La caratterizzazione delle nubi è avvenuta su un campione di oltre 3700 osservazioni al nadir. È stato creato un ampio dataset di spettri sintetici modificando, in un modello iniziale, vari parametri di nube quali composizione chimica, numero e dimensione delle particelle. Un processo di fit è stato applicato alle osservazioni per stabilire quale modello potesse descrivere gli spettri osservati. Si è poi effettuata una analisi statistica sui risultati del campione. Si è ricavata una concentrazione di acido solforico molto elevata nelle nubi basse, pari al 96% in massa, che si discosta dal valore generalmente utilizzato del 75%. Si sono poi integrati i risultati al nadir con uno studio mirato su poche osservazioni al lembo, selezionate in modo da intercettare nel punto di tangenza la colonna atmosferica osservata al nadir, per ricavare informazioni sulle hazes. I risultati di un modello Monte Carlo indicano che il numero e le dimensioni delle particelle previste dal modello base devono essere ridotte in maniera significativa. In particolare si osserva un abbassamento della quota massima delle hazes rispetto ad osservazioni diurne.

(Table DR1) Biogenic silica and chert in the Pacific Ocean, DSDP and ODP data

Evidence for the dissolution of biogenic silica at the base of pelagic sections supports the hypothesis that much of the chert formed in the Pacific derives from the dissolution and reprecipitation of this silica by hydrothermal waters. As ocean bottom waters flow into and through the crust, they become warmer. Initially they remain less saturated with respect to dissolved silica than pore water in the overlying sediments. With the diffusion of heat, dissolved ions, and to some extent the advection of water itself, biogenic silica in the basal part of the sedimentary section is dissolved. Upon conductively cooling, these pore waters precipitate chert layers. The most common thickness for the basal silica-free zone (20 m) lies below the most common height of the top of the chert interval above basement (50 m). This mode of chert formation explains the frequent occurrence of chert layers at very shallow subbottom depths in pelagic sections of the Pacific. It is also consistent with the common occurrence of cherts

Plant-wax, alkenone and major element analyses of ODP Site 659 for the Last Glacial cycle and associated coretop data

We present a hydrologic reconstruction of the Sahara-Sahel transition, covering the complete last glacial cycle (130 ka), based on a combination of plant-wax-specific hydrogen (dD) and carbon isotopes (d13C). The dD and d13C signatures of long-chain n-alkanes from ODP Site 659 off NW Africa reveal a significant anti-correlation. Complementary to published pollen data, we infer that this plant-wax signal reflects sensitive responses of the vegetation cover to precipitation changes in the Sahel region, as well as varying contributions from biomes north of the Sahara (C3 domain) by North-East Trade Winds (NETW). During arid phases, especially the northern parts of the Sahel likely experienced crucial water stress, which resulted in a pronounced contraction of the vegetation cover, thus reducing the amount of C4 plant waxes from the region. The increase in NETW strength during dry periods further promoted a more pronounced C3-plant-wax signal derived from the North African C3 plant domain. During humid periods, the C4-dominated Sahelian environments spread northward into the Saharan realm, in association with lower NETW inputs of C3 plant waxes. Arid-humid cycles deduced from plant-wax dD are in accordance with concomitant changes in weathering intensity reflected in varying major element distributions. Environmental shifts are generally linked to periods with large fluctuations in Northern Hemisphere summer insolation. During Marine Isotope Stages 2 and 3, when insolation variability was low, coupling of the hydrologic regime to alkenone-based estimates of NE Atlantic sea-surface temperatures becomes apparent.

Concentrations and accumulation rates of chemical elements and sediment components in sediments of central equatorial Pacific, DSDP data

Accumulation rates of Mg, Al, Si, Mn, Fe, Ni, Cu, Zn, opal, and calcium carbonate have been calculated from their concentrations in samples from equatorial Deep Sea Drilling Project sites. Maps of element accumulation rates and of Q-mode factors derived from raw data indicate that the flux of trace metals to equatorial Pacific sediments has varied markedly through time and space in response to changes in the relative and absolute influence of several depositional influences: biogenic, detrital, authigenic, and hydrothermal sedimentation. Biologically derived material dominates the sediment of the equatorial Pacific. The distributions of Cu and Zn are most influenced by surface-water biological activity, but Ni, Al, Fe, and Mn are also incorporated into biological material. All of these elements have equatorial accumulation maxima similar to those of opal and calcium carbonate at times during the past 50 m.y. Detritus distributed by trade winds and equatorial surface circulation contributes Al, non-biogenic Si, Fe, and Mg to the region. Detrital sediment is most important in areas with a small supply of biogenic debris and low bulk-accumulation rates. Al accumulation generally increases toward the north and east, indicating its continental source and distribution by the northeast trade winds. Maxima in biological productivity during middle Eocene and latest Miocene to early Pliocene time and concomitant well-developed surface circulation contributed toward temporal maxima in the accumulation rates of Cu, Zn, Ni, and Al in sediments of those ages. Authigenic material is also important only where bulk-sediment accumulation rates are low. Ni, Cu, Zn, and sometimes Mn are associated with this sediment. Fe is almost entirely of hydrothermal origin. Mn is primarily hydrothermal, but some is probably scavenged from sea water by amorphous iron hydroxide floes along with other elements concentrated in hydrothermal sediments, Ni, Cu, and Zn. During the past 50 m.y. all of these elements accumulated over the East Pacific Rise at rates nearly an order of magnitude higher than those at non-rise-crest sites. In addition, factor analysis indicates that some of this material is carried substantial distances to the west of the rise crest. Accumulation rates of Fe in basal metalliferous sediments indicate that the hydrothermal activity that supplied amorphous Fe oxides to the East Pacific Rise areas was most intense during middle Eocene and late Miocene to early Pliocene time.