952 resultados para Data sets storage
Resumo:
Taking into account that the sampling intensity of soil attributes is a determining factor for applying of concepts of precision agriculture, this study aims to determine the spatial distribution pattern of soil attributes and corn yield at four soil sampling intensities and verify how sampling intensity affects cause-effect relationship between soil attributes and corn yield. A 100-referenced point sample grid was imposed on the experimental site. Thus, each sampling cell encompassed an area of 45 m² and was composed of five 10-m long crop rows, where referenced points were considered the center of the cell. Samples were taken from at 0 to 0.1 m and 0.1 to 0.2 m depths. Soil chemical attributes and clay content were evaluated. Sampling intensities were established by initial 100-point sampling, resulting data sets of 100; 75; 50 and 25 points. The data were submitted to descriptive statistical and geostatistics analyses. The best sampling intensity to know the spatial distribution pattern was dependent on the soil attribute being studied. The attributes P and K+ content showed higher spatial variability; while the clay content, Ca2+, Mg2+ and base saturation values (V) showed lesser spatial variability. The spatial distribution pattern of clay content and V at the 100-point sampling were the ones which best explained the spatial distribution pattern of corn yield.
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The aim of this study was to compare the hydrographically conditioned digital elevation models (HCDEMs) generated from data of VNIR (Visible Near Infrared) sensor of ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), of SRTM (Shuttle Radar Topography Mission) and topographical maps from IBGE in a scale of 1:50,000, processed in the Geographical Information System (GIS), aiming the morphometric characterization of watersheds. It was taken as basis the Sub-basin of São Bartolomeu River, obtaining morphometric characteristics from HCDEMs. Root Mean Square Error (RMSE) and cross validation were the statistics indexes used to evaluate the quality of HCDEMs. The percentage differences in the morphometric parameters obtained from these three different data sets were less than 10%, except for the mean slope (21%). In general, it was observed a good agreement between HCDEMs generated from remote sensing data and IBGE maps. The result of HCDEM ASTER was slightly higher than that from HCDEM SRTM. The HCDEM ASTER was more accurate than the HCDEM SRTM in basins with high altitudes and rugged terrain, by presenting frequency altimetry nearest to HCDEM IBGE, considered standard in this study.
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The purpose of this study is to examine how well risk parity works in terms of risk, return and diversification relative to more traditional minimum variance, 1/N and 60/40 portfolios. Risk parity portfolios were constituted of five risk sources; three common asset classes and two alternative beta investment strategies. The three common asset classes were equities, bonds and commodities, and the alternative beta investment strategies were carry trade and trend following. Risk parity portfolios were constructed using five different risk measures of which four were tail risk measures. The risk measures were standard deviation, Value-at-Risk, Expected Shortfall, modified Value-at-Risk and modified Expected Shortfall. We studied also how sensitive risk parity is to the choice of risk measure. The hypothesis is that risk parity portfolios provide better return with the same amount of risk and are better diversified than the benchmark portfolios. We used two data sets, monthly and weekly data. The monthly data was from the years 1989-2011 and the weekly data was from the years 2000-2011. Empirical studies showed that risk parity portfolios provide better diversification since the diversification is made at the risk level. Risk based portfolios provided superior return compared to the asset based portfolios. Using tail risk measures in risk parity portfolios do not necessarily provide better hedge from tail events than standard deviation.
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Tässä diplomityössä jatkettiin Loviisan voimalaitoksen höyryturbiinien suorituskyvyn parannuspotentiaalien tutkimusta. Tavoitteena oli kehittää laitoksen höyryturbiinien suorituskyvyn käytönaikaisia on-line-mittauksia. Selvityksessä perehdyttiin norjalaisen IFE:n kehittämään stationääritilan TEMPOohjelmaan( The Thermal Performance Monitoring And Optimisation system), sen käyttöohjeisiin ja toimintaperiaatteisiin. Työssä esiteltiin laajasti tiedon yhteensovittamisen laskentateoriaa, johon TEMPOn toiminta perustuu. Työssä tarkasteltiin turbiinin todellista paisuntaprosessia, koska sen ymmärtäminen on tärkeässä osassa turbiinin suorituskyvyn valvonnassa. Tutkimuksessa esiteltiin myös turbiineille mahdollisia vikoja sekä niiden syntymisprosesseja. Työssä tarkasteltiin TEMPOn sovittamien tulostiedostojen analysointiohjelman toimivuutta havaitsemalla itse aiheutettuja poikkeamia todellisiin mittaustiedostoihin. Analysointiohjelmalla muodostettuja kuvaajia vertailtiin todellisen prosessin ajotilanteen kuvaajiin ja tarkasteltiin, kuinka poikkeamia on mahdollista havaita kuvaajien avulla. TEMPO-ohjelmalle löydettiin tutkimuksen edetessä kehittämisehdotuksia. Näillä muutoksilla ohjelma saadaan mallintamaan Loviisan voimalaitoksen turbiiniprosessia tarkemmin ja tuloksista saadaan hyödyllisempiä.
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Chaotic dynamical systems exhibit trajectories in their phase space that converges to a strange attractor. The strangeness of the chaotic attractor is associated with its dimension in which instance it is described by a noninteger dimension. This contribution presents an overview of the main definitions of dimension discussing their evaluation from time series employing the correlation and the generalized dimension. The investigation is applied to the nonlinear pendulum where signals are generated by numerical integration of the mathematical model, selecting a single variable of the system as a time series. In order to simulate experimental data sets, a random noise is introduced in the time series. State space reconstruction and the determination of attractor dimensions are carried out regarding periodic and chaotic signals. Results obtained from time series analyses are compared with a reference value obtained from the analysis of mathematical model, estimating noise sensitivity. This procedure allows one to identify the best techniques to be applied in the analysis of experimental data.
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Non-linear functional representation of the aerodynamic response provides a convenient mathematical model for motion-induced unsteady transonic aerodynamic loads response, that accounts for both complex non-linearities and time-history effects. A recent development, based on functional approximation theory, has established a novel functional form; namely, the multi-layer functional. For a large class of non-linear dynamic systems, such multi-layer functional representations can be realised via finite impulse response (FIR) neural networks. Identification of an appropriate FIR neural network model is facilitated by means of a supervised training process in which a limited sample of system input-output data sets is presented to the temporal neural network. The present work describes a procedure for the systematic identification of parameterised neural network models of motion-induced unsteady transonic aerodynamic loads response. The training process is based on a conventional genetic algorithm to optimise the network architecture, combined with a simplified random search algorithm to update weight and bias values. Application of the scheme to representative transonic aerodynamic loads response data for a bidimensional airfoil executing finite-amplitude motion in transonic flow is used to demonstrate the feasibility of the approach. The approach is shown to furnish a satisfactory generalisation property to different motion histories over a range of Mach numbers in the transonic regime.
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Wind power is a low-carbon energy production form that reduces the dependence of society on fossil fuels. Finland has adopted wind energy production into its climate change mitigation policy, and that has lead to changes in legislation, guidelines, regional wind power areas allocation and establishing a feed-in tariff. Wind power production has indeed boosted in Finland after two decades of relatively slow growth, for instance from 2010 to 2011 wind energy production increased with 64 %, but there is still a long way to the national goal of 6 TWh by 2020. This thesis introduces a GIS-based decision-support methodology for the preliminary identification of suitable areas for wind energy production including estimation of their level of risk. The goal of this study was to define the least risky places for wind energy development within Kemiönsaari municipality in Southwest Finland. Spatial multicriteria decision analysis (SMCDA) has been used for searching suitable wind power areas along with many other location-allocation problems. SMCDA scrutinizes complex ill-structured decision problems in GIS environment using constraints and evaluation criteria, which are aggregated using weighted linear combination (WLC). Weights for the evaluation criteria were acquired using analytic hierarchy process (AHP) with nine expert interviews. Subsequently, feasible alternatives were ranked in order to provide a recommendation and finally, a sensitivity analysis was conducted for the determination of recommendation robustness. The first study aim was to scrutinize the suitability and necessity of existing data for this SMCDA study. Most of the available data sets were of sufficient resolution and quality. Input data necessity was evaluated qualitatively for each data set based on e.g. constraint coverage and attribute weights. Attribute quality was estimated mainly qualitatively by attribute comprehensiveness, operationality, measurability, completeness, decomposability, minimality and redundancy. The most significant quality issue was redundancy as interdependencies are not tolerated by WLC and AHP does not include measures to detect them. The third aim was to define the least risky areas for wind power development within the study area. The two highest ranking areas were Nordanå-Lövböle and Påvalsby followed by Helgeboda, Degerdal, Pungböle, Björkboda, and Östanå-Labböle. The fourth aim was to assess the recommendation reliability, and the top-ranking two areas proved robust whereas the other ones were more sensitive.
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Benzodiazepines (BZD) and benzodiazepine related drugs (RD) are the most commonly used psychotropics among the aged. The use of other psychotropics taken concomitantly with BZD/ RD or their cognitive effects with BZD/RD have not been studied frequently. The aim of this academic thesis was to describe and analyse relationships between the use of BZD/RD alone or concomitantly with antipsychotics, antidepressants, opioids, antiepileptics, opioids and anticholinergics in the aged and their health. Especially, the relationships between long-term use of BZD/RD and cognitive decline were studied. Additionally, the effect of melatonin on BZD/RD withdrawal and the cognitive effects of BZD/RD withdrawal were studied. This study used multiple data sets: the first study (I) was based on clinical data containing aged patients (≥65 years; N=164) admitted to Pori City Hospital due to acute disease. The second data set (Studies II and III) was based on population-based data from the Lieto Study, a clinico-epidemiological longitudinal study carried out among the aged (≥65 years) in the municipality of Lieto. Follow-up data was formed by combining the cohort data collected in 1990-1991 (N=1283) and in 1998-1999 (N=1596) from those who participated in both cohorts (N=617). The third data set (Studies IV and V) was based on the Satauni Study’s data. This study was performed in the City of Pori in 2009-2010. In the RCT part of the Satauni Study, ninety-two long-term users of BZD/RD were withdrawn from their drugs using melatonin against placebo. The change of their cognitive abilities was measured during and after BZD/ RD withdrawal. BZD/RD use was related to worse cognitive and functional abilities, and their use may predict worse cognitive outcomes compared with BZD/RD non-users. Hypnotic use of BZD/RD could be withdrawn with psychosocial support in motivated participants, but melatonin did not improve the withdrawal results compared to those with placebo. Cognitive abilities in psychomotor tests did not show, or showed only modest, improvements for up to six months after BZD/RD withdrawal. This suggests that the cognitive effects of BZD/RD may be longlasting or permanent.
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Suomalaisten ja saksalaisten arkikeskustelujen välillä on sekä yhtäläisyyksiä että eroja. Tässä saksalaisen filologian alaan kuuluvassa tutkimuksessa tarkastellaan yhtä keskeistä arkikeskustelun toimintoa, puhelinkeskustelun lopetusta, suomen- ja saksanpuhujien tuottamana. Aineistona on käytetty suomen- ja saksankielisten äidinkielisten puhujien tätä tutkimusta varten nauhoittamia henkilökohtaisia luonnollisia puhelinkeskusteluja. Aineistoon valikoitui 12 suomalaista ja 12 saksalaista puhelua. Nauhoitteiden käyttöön on saatu asianmukainen lupa kaikilta osapuolilta. Puhelut on litteroitu saksalaisella kielialueella vakiintuneen GAT-litterointisysteemin mukaan. Teoreettis-metodisena kehyksenä on kaksi tutkimusalaa, vuorovaikutuslingvistiikka ja kielten vertailu. Vuorovaikutuslingvistinen tarkastelu keskittyy havaintoihin vuorojen ja puheen sekvenssien rakenteesta. Vuorojen merkitysten tulkinnassa hyödynnetään systemaattisesti prosodian antamia vihjeitä. Tuloksena on yksittäisten lopetusten keskustelunanalyyttinen lähikuvaus, jonka pohjalta määritellään kulloisenkin lopetuksen sekvenssirakenne. Kaikki lopetukset olivat siltä osin yhteneväisiä, että niissä kaikissa havaittiin ainakin aloittava, tulevaan tapaamiseen viittaava sekä lopputervehdyksiin johtava sekvenssi. Sekvenssirakenteen variaatioiden pohjalta aineiston lopetukset voidaan kuitenkin jaotella ryhmiin. Sekä suomen- että saksankielisessä aineistossa havaittiin kolmentyyppisiä lopetuksia: kompakteja, komplekseja ja keskeytettyjä lopetuksia. Ryhmittely kolmeen tyyppiin on avuksi seuraavassa kuvausvaiheessa, jossa verrataan suomen- ja saksankielisiä lopetuksia toisiinsa. Samanaikaisesti kun tutkimus valottaa kohtia, joissa kaksi aineistosettiä yhtenevät ja eroavat, se myös esittää, mitkä vuorovaikutuksen tasot soveltuvat kieltenvälisen vertailun kohteiksi. Pohdintaa siitä, mitä vuorovaikutuksen tasoja kieltenväliseen vertailuun voidaan sisällyttää, onkin toistaiseksi esitetty verrattain vähän. Työ siis rakentaa siltaa vuorovaikutuslingvistisen ja kontrastiivisen kielitieteen välille.
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A floristic and structural survey of a natural grassland community was conducted on Morro do Osso, a granitic hill in Porto Alegre, RS, Brazil. Structural data were surveyed in 39 one square meter plots placed over two major grassland areas. An accidental fire has occurred in one of the areas approximately one year prior to our survey, leading to further analysis of parameters differences between sites. The floristic list contains 282 species, whereas the structural survey has found 161 species. Families with highest accumulated importance values were Poaceae, Asteraceae and Fabaceae. The diversity and evenness indexes were 4.51 nats ind-1 and 0.86, respectively. Cluster analysis denoted two groups coinciding with the areas distinguished by the fire disturbance. A similarity analysis between our data and two other data sets from nearby granitic hills resulted in 28% to 35% similarity, with equivalent species-family distribution and many common dominant species, corroborating the concept of a continuous flora along the South Brazilian granitic hills.
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The amount of biological data has grown exponentially in recent decades. Modern biotechnologies, such as microarrays and next-generation sequencing, are capable to produce massive amounts of biomedical data in a single experiment. As the amount of the data is rapidly growing there is an urgent need for reliable computational methods for analyzing and visualizing it. This thesis addresses this need by studying how to efficiently and reliably analyze and visualize high-dimensional data, especially that obtained from gene expression microarray experiments. First, we will study the ways to improve the quality of microarray data by replacing (imputing) the missing data entries with the estimated values for these entries. Missing value imputation is a method which is commonly used to make the original incomplete data complete, thus making it easier to be analyzed with statistical and computational methods. Our novel approach was to use curated external biological information as a guide for the missing value imputation. Secondly, we studied the effect of missing value imputation on the downstream data analysis methods like clustering. We compared multiple recent imputation algorithms against 8 publicly available microarray data sets. It was observed that the missing value imputation indeed is a rational way to improve the quality of biological data. The research revealed differences between the clustering results obtained with different imputation methods. On most data sets, the simple and fast k-NN imputation was good enough, but there were also needs for more advanced imputation methods, such as Bayesian Principal Component Algorithm (BPCA). Finally, we studied the visualization of biological network data. Biological interaction networks are examples of the outcome of multiple biological experiments such as using the gene microarray techniques. Such networks are typically very large and highly connected, thus there is a need for fast algorithms for producing visually pleasant layouts. A computationally efficient way to produce layouts of large biological interaction networks was developed. The algorithm uses multilevel optimization within the regular force directed graph layout algorithm.
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Bioanalytical data from a bioequivalence study were used to develop limited-sampling strategy (LSS) models for estimating the area under the plasma concentration versus time curve (AUC) and the peak plasma concentration (Cmax) of 4-methylaminoantipyrine (MAA), an active metabolite of dipyrone. Twelve healthy adult male volunteers received single 600 mg oral doses of dipyrone in two formulations at a 7-day interval in a randomized, crossover protocol. Plasma concentrations of MAA (N = 336), measured by HPLC, were used to develop LSS models. Linear regression analysis and a "jack-knife" validation procedure revealed that the AUC0-¥ and the Cmax of MAA can be accurately predicted (R²>0.95, bias <1.5%, precision between 3.1 and 8.3%) by LSS models based on two sampling times. Validation tests indicate that the most informative 2-point LSS models developed for one formulation provide good estimates (R²>0.85) of the AUC0-¥ or Cmax for the other formulation. LSS models based on three sampling points (1.5, 4 and 24 h), but using different coefficients for AUC0-¥ and Cmax, predicted the individual values of both parameters for the enrolled volunteers (R²>0.88, bias = -0.65 and -0.37%, precision = 4.3 and 7.4%) as well as for plasma concentration data sets generated by simulation (R²>0.88, bias = -1.9 and 8.5%, precision = 5.2 and 8.7%). Bioequivalence assessment of the dipyrone formulations based on the 90% confidence interval of log-transformed AUC0-¥ and Cmax provided similar results when either the best-estimated or the LSS-derived metrics were used.
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Tutkimus sijoittuu varhaiskasvatuksen hajautetun organisaation kontekstiin, mutta tulokset ovat siirrettävissä muihinkin suomalaisiin kasvatus- ja opetustoimen organisaatioihin. Hajautettujen organisaatioiden tutkimus on ollut varhaiskasvatuksen kentällä vielä vähäistä, vaikka organisaatiomallin vaikutukset johtajuuden toteuttamiselle ovat merkittävät. Hajautetulla organisaatiolla varhaiskasvatuksessa tarkoitetaan sitä, että yhden johtajan alaisuudessa on monta eri päiväkotia tai erilaisia päivähoitomuotoja. Tämä organisaatiomalli on yhä enenevässä määrin kasvava suomalaisessa varhaiskasvatuksessa. Varhaiskasvatuksen hajautettujen organisaatioiden tutkimuksessa on aiemmin tarkasteltu johtajan ja työntekijöiden ja työntekijöiden keskinäisiä ammatillisia suhteita. Tässä tutkimuksessa näkökulma painottuu johtamiseen ja työskentelyyn hajautetuissa organisaatiossa sinänsä sekä myös laadunarviointiin sekä pedagogiikkaan. Viitekehyksenä tutkimuksessa on LMX-teoria (leader-member-exchange, johtajuuden vaihtoteoria), jossa tarkastellaan esimies-alaissuhdetta ja siihen kiinteästi liittyvää luottamuksen käsitettä. Luottamuksen merkitys hajautetuissa organisaatioissa korostuu, koska esimies ei ole fyysisesti päivittäin läsnä työntekijöiden arjessa. Tutkimuksessa tarkastellaan hajautetuissa varhaiskasvatuksen organisaatioissa työskentelyä seuraavien tutkimuskysymysten avulla: 1) Mitkä ovat varhaiskasvatuksen hajautettujen organisaatioiden johtamisen erityispiirteet? 2) Miten eri työntekijäryhmät kokevat hajautetussa organisaatiossa työskentelyn? 3) Millaisia kokemuksia esimiehillä ja työntekijöillä on heidän yksiköissään toteutetusta laadunarvioinnista? 4) Millaiseksi työntekijät ja esimiehet kokevat esimieheltään saadun tuen? Tutkimuksessa oli kolme eri aineistoa. Ensimmäinen aineisto koostui 11 hajautetun organisaation johtajan haastattelusta. Toinen aineisto (n = 223) sisälsi haastateltujen esimiesten lomakevastausten lisäksi heidän alaisuudessaan toimivien työntekijöiden, 10 esimieskoulutukseen osallistuneen johtajan sekä kolmen erillisyksikön työntekijöiden vastaukset. Kolmas aineisto oli kerätty pääkaupunkiseudulta varhaiskasvatuksen johtajilta lomakekyselynä (n = 112). Aineistoa on analysoitu teorialähtöisen ja aineistolähtöisen sisällönanalyysin ja tilastollisten analyysien avulla Tulokset osoittavat, että johtajat kokivat hallinnollisten töiden vievän paljon aikaa. Esimiehen kanssa eri työpaikassa työskentelevät työntekijät hahmottivat koko organisaation selkeämmin kuin esimiehen kanssa fyysisesti samassa paikassa työskentelevät. Esimiesten käsitysten mukaan laadunarviointia suoritettiin enemmän kuin mitä työntekijöiden mukaan. Työntekijät kaipasivat esimiehiltään tukea yhteistyöhön ja vuorovaikutukseen, pedagogiseen ohjaukseen, kehittämiseen ja toiminnan resursseihin liittyen. Erillisyksikössä työskentelevät kokivat saavansa enemmän tukea kuin esimiehen kanssa fyysisesti samassa yksikössä työskentelevät työntekijät. Sekä esimieheltä saadun pedagogisen tuen että luottamuksen kokemukset kiinnittävät tämän tutkimuksen tulosten mukaan huomion rakenteiden merkitykseen hajautetuissa organisaatioissa. Arviointiin, pedagogiseen tukeen ja tiedonkulkuun liittyvien rakenteiden huomioiminen helpottaa hajautetussa organisaatiossa johtamista. Edellisten lisäksi johtajan selkeä visio omasta johtamistyöstään ja jaetun johtajuuden hyödyntäminen edesauttavat työn hallinnan kokemuksia.
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Escherichia coli, as a model microorganism, was treated in phosphate-buffered saline under high hydrostatic pressure between 100 and 300 MPa, and the inactivation dynamics was investigated from the viewpoint of predictive microbiology. Inactivation data were curve fitted by typical predictive models: logistic, Gompertz and Weibull functions. Weibull function described the inactivation curve the best. Two parameters of Weibull function were calculated for each holding pressure and their dependence on holding pressure was obtained by interpolation. With the interpolated parameters, inactivation curves were simulated and compared with the experimental data sets.
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Kalman filter is a recursive mathematical power tool that plays an increasingly vital role in innumerable fields of study. The filter has been put to service in a multitude of studies involving both time series modelling and financial time series modelling. Modelling time series data in Computational Market Dynamics (CMD) can be accomplished using the Jablonska-Capasso-Morale (JCM) model. Maximum likelihood approach has always been utilised to estimate the parameters of the JCM model. The purpose of this study is to discover if the Kalman filter can be effectively utilized in CMD. Ensemble Kalman filter (EnKF), with 50 ensemble members, applied to US sugar prices spanning the period of January, 1960 to February, 2012 was employed for this work. The real data and Kalman filter trajectories showed no significant discrepancies, hence indicating satisfactory performance of the technique. Since only US sugar prices were utilized, it would be interesting to discover the nature of results if other data sets are employed.