Search results for "statistical analysis"

Has the Introduction of Bitcoin Futures on Regulated Exchanges Decreased Price Volatility?

2019

Master's thesis Business Administration BE501 - University of Agder 2019 Bitcoin is a tremendously debated phenomenon in the world of finance and in recent the scientific literature on the topic has expanded. In this thesis,the bitcoin to US dollar exchange rate is examined through various conditional variance models to describe its highly volatile nature. We examine whether the introduction of bitcoin futurescontractsin late 2017 has had a decreasing impact on price volatility by estimatingthe unconditional variance. The log-return of the bitcoin exchange rate is analysed,and there is evidence of volatility clustering and time-varying volatility. Consequently, the variance is modelled thro…

Modalitātes lietojums tiešsaistes laikrakstu rakstos Lielbritānijā un ASV par politiskām tēmām

2020

Iepriekšējie pētījumi par modalitātes lietojumu laikrakstu rakstos atklāja, ka žurnālisti mēdz ietekmēt lasītājus un sniegt faktu subjektīvu interpretāciju, kad tiek gaidīts objektīvs notikumu atspoguļojums. Tāpēc šī darba mērķis bija analizēt modalitātes lietojumu septiņpadsmit tiešsaistes laikrakstu rakstos divos Lielbritānijas un divos ASV laikrakstos par Brexit. Pētījumā izmantotās metodes ir diskursa analīze un statistiskā analīze. Rezultāti liecina, ka visvairāk lietotais modālais darbības vārds abu valstu laikrakstos ir will, kas izteica pārliecības nozīmi ar pierādījumu palīdzību, un norādīja, ka priekšroka tiek dota patiesībai. Pārējie modālie darbības vārdi would un could dominēja…

2019

Abstract. The cumulative occurrence of heavy precipitation and flood events during recent years in various Central European locations emphasises the urgent need to improve extreme rainfall observations and forecasts. Precipitation gauges based on a weighing system allow the recording of intense short-term precipitation events with a very high temporal resolution (down to 1 min). In this study, observational data that were collected during the period 2000 to 2016 for 126 stations of two corresponding measuring networks in the Central German state of Hesse were investigated for the first time to answer the following questions: (1) Are the recorded high-resolution precipitation data plausible …

Knowledge and Beliefs About Developmental Dyslexia: A Comparison Between Pre-Service and In-Service Peruvian Teachers

2017

The purpose of this study was to investigate the knowledge, misconceptions, and knowledge gaps of Peruvian pre-service teachers (PSTs) and in-service teachers (ISTs). To do so, 112 PSTs and 113 ISTs completed the Knowledge and Beliefs About Developmental Dyslexia Scale (KBDDS). Results show that ISTs scored significantly higher than PSTs. Moreover, misconceptions and lack of information were higher in PSTs. The most noteworthy misconceptions were that dyslexia is due to poor visual perception and that letter or word reversals are the most important criterion in the identification of dyslexia. Age, years of teaching experience, prior exposure to a child with dyslexia, and self-efficacy were …

Effective field theory search for high-energy nuclear recoils using the XENON100 dark matter detector

2017

International audience; We report on weakly interacting massive particles (WIMPs) search results in the XENON100 detector using a nonrelativistic effective field theory approach. The data from science run II (34  kg×224.6 live days) were reanalyzed, with an increased recoil energy interval compared to previous analyses, ranging from (6.6–240)  keVnr. The data are found to be compatible with the background-only hypothesis. We present 90% confidence level exclusion limits on the coupling constants of WIMP-nucleon effective operators using a binned profile likelihood method. We also consider the case of inelastic WIMP scattering, where incident WIMPs may up-scatter to a higher mass state, and …

Influence of Site and Check Dam Characteristics on Sediment Retention and Structure Conservation in a Mexican River

2020

Previously, in a large river of Mexico regulated by more than 200 check dams, we demonstrated that vegetation cover and channel characteristics were the dominant factors on the structure conditions and capacity to store sediments. This study focuses on other categorical (i.e., check dam type and location, soil texture and land use) and numerical (i.e. water discharge, check dam dimensions) variables, to whom statistical analysis is applied, in order to assess their influence on sediment filling degree and conditions (functional or destroyed) of the check dams in the same river. ANOVA has shown that: (i) check dam type (gabion or stone) and location (headwater, middle or valley reaches), and…

Una nuova teoria per lo studio dei processi di efflusso dagli stramazzi

2011

Il processo di efflusso da uno stramazzo, di notevole interesse per le applicazioni pratiche, viene studiato applicando l’analisi dimensionale e la teoria dell’autosimilitudine incompleta. La nuova scala teorica di efflusso dedotta per gli stramazzi, in parete sottile e grossa e di differente forma geometrica, viene verificata facendo ricorso sia alle misure disponibili in letteratura sia ad apposite sperimentazioni di laboratorio.

The effect of whole genome amplification on samples originating from more than one donor

2006

Abstract In this study, the GenomiPhi™ DNA Amplification Kit (Amersham Biosciences) was used to investigate the potential of whole genome amplification (WGA) when considering samples originating from more than one donor. DNA was extracted from blood samples, quantified and normalised before being mixed in ratios of 1:1, 1:3, 1:7 and 1:15. Proportions were checked using standard STR analysis before being subjected to WGA. Once amplified using GenomiPhi™, the ratios were again checked. Relative proportions were found to be maintained in the 1:1 and 1:3 ratios following WGA; the observed peak ratios were found to match the expected peak ratios regardless of the starting concentration of DNA. W…

Joint probability distributions for wind speed and direction. A case study in Sicily

2015

In this study we analyze data of hourly average wind speed and direction measured at three different sampling stations located in Sicily (Italy) and provide a statistical model for their joint probability density function. Singly truncated from below Normal Weibull mixture distribution and a linear combination of von Mises distributions are used to model wind speed and direction. Sites with heterogeneous local conditions (prevailing wind direction and/or elevation) have been considered in order to investigate the reliability of the model here taken into consideration.

Varietal and geographic classification of french red wines in terms of major acids

1989

Concentrations of acids other than malic and lactic appeared to be related more to area of production than to grape variety. These variables (2- hydroxyglutaric, butyric and isovaleric acid concentrations) were attributed to differences in the technological process used for vinification in the various areas. Shikimic and galacturonic acids were helpful for classifying and discriminating wine varieties. Principal component analysis characterised Cabernet Franc, Grenache and Carignan wines well by their acid content but failed to discriminate Merlot from Cabernet Sauvignon and Cinsault. Stepwise discriminant analysis allowed a clear separation of all wines according to the different varieties…