Analisi dei limiti imposti dai dati sulla previsione delle rotture delle condotte di acquedotto

Nella memoria vengono analizzati i dati relativi alle rotture registrate nella rete di distribuzione idrica di Trondheim (Norvegia) al fine di valutare se la storia pregressa delle rotture possa fornire indicazioni sullo stato strutturale della rete confrontabili con quanto desumibile applicando la teoria dell\u2019affidabilit\ue0 per componenti riparabili. In particolare, dopo un\u2019analisi statistica dei dati, lo studio evidenzia i limiti imposti dal troncamento a sinistra e a destra della finestra temporale cui i dati si riferiscono. Il modello CASSES, sviluppato da Cemagref in Francia (Le Gat, 2009), \ue8 stato modificato al fine di superare tali limitazioni: una parte del campione delle rotture registrate \ue8 stato utilizzato per calibrare i parametri del modello di previsione delle rotture di ciascuna classe omogenea di condotte, mentre la seconda parte \ue8 stata confrontata con le rotture calcolate dai modelli cos\uec calibrati, al fine di selezionare il vettore di parametri che fornisce la migliore previsione

Den globala läraren – en kvantitativ undersökning av lärarstudenters attityder till VFU utomlands vid Göteborgs universitet

Internationalisering är ett begrepp som under 000-talet fått allt större plats i det offentliga rummet. På senaste tiden har allt fler universitet runt om i landet satsat mycket på att just internationalisera utbildningen för att vara attraktiv på arbetsmarknaden. Göteborgs universitet har fått mycket beröm just för deras satsning på detta och lärarutbildningen inte minst. Dock så visar statistik på att lärarstudenter är en av grupper av studenter som minst utnyttjar möjligheten till ett utbyte under sina studier. Denna studies syfte var att undersöka vad lärarstudenter som går sin sista termin på lärarprogrammet Lp01 har för åsikter och attityder till möjligheten att göra en internationaliserad verksamhetsförlagd utbildning (VFU). Studien genomfördes genom en kvantitativ metod där en enkätundersökning skapades på webben. Enkäten skickades till 301 lärarstudenter vid Göteborgs universitet varav 46 studenter besvarades enkäten. Resultatet visade att en majoritet av lärarstudenterna i studien är positiva till VFU utomlands, men att endast en minoritet av respondenterna i studien genomfört en sådan. Studenterna ansåg själva att positiva effekter för dem som blivande lärare, såsom ökad kunskap för andra länders skolsystem och kultur, men även personliga effekter, såsom ökade språkkunskaper och ökat självförtroende. De negativa effekterna av ett utbyte var i stort sett kortsiktiga effekter, såsom att studenternas ekonomiska situation påverkas och att organisationen av ett utbyte är krånglig. En minoritet såg långsiktiga negativa effekter, där studenterna oroade sig för att missa viktig undervisning i Sverige som de som inte åker på utbyte får och att de därför skulle få sämre inblick i det svenska systemet. Sammanfattningsvis så trots GUs prioritering av internationalisering i styrdokument och trots studenterna i studiens positiva inställning så tycks resultatet visa på att detta inte har lett till någon stor utveckling i praktiken då endast få lärarstudenter genomför ett utbyte under sin studietid

THE IMPORTANCE OF CORRECT STAGE GROUPING IN ONCOLOGY - RESULTS OF A NATIONWIDE STUDY OF OROPHARYNGEAL CARCINOMA IN THE NETHERLANDS

Contains fulltext : 21312___.PDF (publisher's version ) (Open Access

Spectral tissue sensing to identify intra- and extravascular needle placement - A randomized single-blind controlled trial

Contains fulltext : 175657.pdf (publisher's version ) (Open Access)Safe vascular access is a prerequisite for intravenous drug admission. Discrimination between intra- and extravascular needle position is essential for procedure safety. Spectral tissue sensing (STS), based on optical spectroscopy, can provide tissue information directly from the needle tip. The primary objective of the trial was to investigate if STS can reliably discriminate intra-vascular (venous) from non-vascular punctures. In 20 healthy volunteers, a needle with an STS stylet was inserted, and measurements were performed for two intended locations: the first was subcutaneous, while the second location was randomly selected as either subcutaneous or intravenous. The needle position was assessed using ultrasound (US) and aspiration. The operators who collected the data from the spectral device were blinded to the insertion and ultrasonographic visualization procedure and the physician was blinded to the spectral data. Following offline spectral analysis, a prediction of intravascular or subcutaneous needle placement was made and compared with the "true" needle tip position as indicated by US and aspiration. Data for 19 volunteers were included in the analysis. Six out of 8 intended vascular needle placements were defined as intravascular according to US and aspiration. The remaining two intended vascular needle placements were negative for aspiration. For the other 11 final needle locations, the needle was clearly subcutaneous according to US examination and no blood was aspirated. The Mann-Whitney U test yielded a p-value of 0.012 for the between-group comparison. The differences between extra- and intravascular were in the within-group comparison computed with the Wilcoxon signed-rank test was a p-value of 0.022. In conclusion, STS is a promising method for discriminating between intravascular and extravascular needle placement. The information provided by this method may complement current methods for detecting an intravascular needle position

The Design of Sparse Direct Solvers using Object-Oriented Techniques

We describe our experience in designing object-oriented software for sparse direct solvers. We discuss, a library of sparse matrix ordering codes, and, a package that implements the factorization and triangular solution steps of a direct solver. We discuss the goals of our design: managing complexity, simplicity of interface, exibility, extensibility, safety, and efficiency. High performance is obtained by carefully implementing the computationally intensive kernels and by making several tradeo s to balance the conflicting demands of efficiency and good software design. Some of the missteps that we made in the course of this work are also described