9 resultados para Relative standard deviations
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
This MSc work was done in the project of BIOMECON financed by Tekes. The prime target of the research was, to develop methods for separation and determination of carbohydrates (sugars), sugar acids and alcohols, and some other organic acids in hydrolyzed pulp samples by capillary electrophoresis (CE) using UV detection. Aspen, spruce, and birch pulps are commonly used for production of papers in Finland. Feedstock components in pulp predominantly consist of carbohydrates, organic acids, lignin, extractives, and proteins. Here in this study, pulps have been hydrolyzed in analytical chemistry laboratories of UPM Company and Lappeenranta University in order to convert them into sugars, acids, alcohols, and organic acids. Foremost objective of this study was to quantify and identify the main and by-products in the pulp samples. For the method development and optimization, increased precision in capillary electrophoresis was accomplished by calculating calibration data of 16 analytes such as D-(-)-fructose, D(+)-xylose, D(+)-mannose, D(+)-cellobiose, D-(+)-glucose, D-(+)-raffinose, D(-)-mannitol, sorbitol, rhamnose, sucrose, xylitol, galactose, maltose, arabinose, ribose, and, α-lactose monohydratesugars and 16 organic acids such as D-glucuronic, oxalic, acetic, propionic, formic, glycolic, malonic, maleic, citric, L-glutamic, tartaric, succinic, adipic, ascorbic, galacturonic, and glyoxylic acid. In carbohydrate and polyalcohol analyses, the experiments with CE coupled to direct UV detection and positive separation polarity was performed in 36 mM disodium hydrogen phosphate electrolyte solution. For acid analyses, CE coupled indirect UV detection, using negative polarity, and electrolyte solution made of 2,3 pyridinedicarboxylic acid, Ca2+ salt, Mg2+ salts, and myristyltrimethylammonium hydroxide in water was used. Under optimized conditions, limits of detection, relative standard deviations and correlation coefficients of each compound were measured. The optimized conditions were used for the identification and quantification of carbohydrates and acids produced by hydrolyses of pulp. The concentrations of the analytes varied between 1 mg – 0.138 g in liter hydrolysate.
Resumo:
Diplomityössä esitetään menetelmä populaation monimuotoisuuden mittaamiseen liukulukukoodatuissa evoluutioalgoritmeissa, ja tarkastellaan kokeellisesti sen toimintaa. Evoluutioalgoritmit ovat populaatiopohjaisia menetelmiä, joilla pyritään ratkaisemaan optimointiongelmia. Evoluutioalgoritmeissa populaation monimuotoisuuden hallinta on välttämätöntä, jotta suoritettu haku olisi riittävän luotettavaa ja toisaalta riittävän nopeaa. Monimuotoisuuden mittaaminen on erityisen tarpeellista tutkittaessa evoluutioalgoritmien dynaamista käyttäytymistä. Työssä tarkastellaan haku- ja tavoitefunktioavaruuden monimuotoisuuden mittaamista. Toistaiseksi ei ole ollut olemassa täysin tyydyttäviä monimuotoisuuden mittareita, ja työn tavoitteena on kehittää yleiskäyttöinen menetelmä liukulukukoodattujen evoluutioalgoritmien suhteellisen ja absoluuttisen monimuotoisuuden mittaamiseen hakuavaruudessa. Kehitettyjen mittareiden toimintaa ja käyttökelpoisuutta tarkastellaan kokeellisesti ratkaisemalla optimointiongelmia differentiaalievoluutioalgoritmilla. Toteutettujen mittareiden toiminta perustuu keskihajontojen laskemiseen populaatiosta. Keskihajonnoille suoritetaan skaalaus, joko alkupopulaation tai nykyisen populaation suhteen, riippuen lasketaanko absoluuttista vai suhteellista monimuotoisuutta. Kokeellisessa tarkastelussa havaittiin kehitetyt mittarit toimiviksi ja käyttökelpoisiksi. Tavoitefunktion venyttäminen koordinaattiakseleiden suunnassa ei vaikuta mittarin toimintaan. Myöskään tavoitefunktion kiertäminen koordinaatistossa ei vaikuta mittareiden tuloksiin. Esitetyn menetelmän aikakompleksisuus riippuu lineaarisesti populaation koosta, ja mittarin toiminta on siten nopeaa suuriakin populaatioita käytettäessä. Suhteellinen monimuotoisuus antaa vertailukelpoisia tuloksia riippumatta parametrien lukumäärästä tai populaation koosta.
Resumo:
Tutkimuksen tarkoituksena on selvittää, kumpi on suomalaisen sijoittajan näkökulmasta tehokkaampi tapa allokoida portfolio Euroopan alueelle, maa- vai toimialalähestymistapa. Tätä tutkitaan käyttämällä aineistoa vuosilta 1999-2003. Tilanne ennen vuotta 1999 on aikaisempien tutkimusten perusteella melko hyvin selvillä, joten tutkimus antaa tuoretta tietoa siitä, miten poikkeuksellinen tuottohistoria vaikuttaa portfolion allokointiin. Aihetta tutkitaan käyttämällä 16 Euroopan alueen maaindeksiä ja kymmentä toimialaindeksiä. Indeksit ovat logaritmisia nettotuottoindeksejä, ja niistä on laskettu korrelaatiot, keskihajonnat sekä tehokkaat rintamat. Indekseistä on myös muodostettu 11 esimerkkiportfoliota, joiden avulla on analysoitu erilaisten portfolioiden suorituskykyä. Tuloksien mukaan maakohtaisella sijoitusstrategialla on etenkin laskevilla markkinoilla mahdollisuus saavuttaa parempi riski/tuotto-suhde, vaikka sijoitettaisiin pelkästään toimialoihin, joita yleisen käsityksen mukaan kannattaa suosia laskevilla markkinoilla. Toimialasijoittaminen taas tarjoaa hieman parempia mahdollisuuksia portfolion hajautukseen. Hajautuksen hyödyt suomalaiselle sijoittajalle tulivat tutkimuksessa selvästi esiin. Toimialasijoittamisesta on suomalaiselle sijoittajalle erityistä hyötyä hajautuksen kannalta, koska näin voidaan valita toimialoja, joiden paino Suomen markkinaindeksissä on vähäinen.
Resumo:
The purpose of this study was to evaluate the competence of nurse teachers, who are teaching nursing at polytechnic level in Finland. The following research questions were framed for the study: What kind of evaluation nurse teachers of their nursing competence, teaching skills, evaluation skills, personality factors and relationships with students. The data were collected by a questionnaire (A Tool for Evaluation of Requirements of Nurse Teacher, ERNT). The questionnaire regarded background factors and 20 statements divided in five categories. The five competence categories were: Nursing competence, Teaching skills, Evaluation skills, Personality factors and Relationships with students. The evaluation scale was a 5-point Likert-scale. The respondents were nurse teachers, teacher for emergency nursing, public health nurse and midwifery teachers from all polytechnics in Finland. Response rate to the questionnaire was 46 % (n=342). The data were analysed by using descriptive statistics. Mean scores and standard deviations for each item were calculated. Category scores were obtained by summing scores of all items within a category. The results of this study showed that nurse teacher evaluated their competence on a high level. Concerning the category Relationships with students (mean 4.61, standard deviation 0.71) they got the highest averages. The lowest scores were gained regarding the requirements associated with teaching skills (mean 4.30, standard deviation 0.82). Concerning a single question, the best score was achieved in ability to take students seriously (mean 4.66, standard deviation 0.71) and the lowest score was achieved for their guidance of students to advance in decision making (mean 4.15, Std 0.69). The nurse teachers evaluated themselves with relatively high scores concerning competence categories as a hole. In future it is important to study nurse teacher competence with students or authorities of health service.
Resumo:
The purpose of this research was to do a repeated cross-sectional research on class teachers who study in the 4th year and also graduated at the Faculty of Education, University of Turku between the years of 2000 through 2004. Specifically, seven research questions were addressed to target the main purpose of the study: How do class teacher education masters’ degree senior students and graduates rate “importance; effectiveness; and quality” of training they have received at the Faculty of Education? Are there significant differences between overall ratings of importance; effectiveness and quality of training by year of graduation, sex, and age (for graduates) and sex and age (for senior students)? Is there significant relationship between respondents’ overall ratings of importance; effectiveness and their overall ratings of the quality of training and preparation they have received? Are there significant differences between graduates and senior students about importance, effectiveness, and quality of teacher education programs? And what do teachers’ [Graduates] believe about how increasing work experience has changed their opinions of their preservice training? Moreover the following concepts related to the instructional activities were studied: critical thinking skills, communication skills, attention to ethics, curriculum and instruction (planning), role of teacher and teaching knowledge, assessment skills, attention to continuous professional development, subject matters knowledge, knowledge of learning environment, and using educational technology. Researcher also tried to find influence of some moderator variables e.g. year of graduation, sex, and age on the dependent and independent variables. This study consisted of two questionnaires (a structured likert-scale and an open ended questionnaire). The population in study 1 was all senior students and 2000-2004 class teacher education masters’ degree from the departments of Teacher Education Faculty of Education at University of Turku. Of the 1020 students and graduates the researcher was able to find current addresses of 675 of the subjects and of the 675 graduates contacted, 439 or 66.2 percent responded to the survey. The population in study 2 was all class teachers who graduated from Turku University and now work in the few basic schools (59 Schools) in South- West Finland. 257 teachers answered to the open ended web-based questions. SPSS was used to produce standard deviations; Analysis of Variance; Pearson Product Moment Correlation (r); T-test; ANOVA, Bonferroni post-hoc test; and Polynomial Contrast tests meant to analyze linear trend. An alpha level of .05 was used to determine statistical significance. The results of the study showed that: A majority of the respondents (graduates and students) rated the overall importance, effectiveness and quality of the teacher education programs as important, effective and good. Generally speaking there were only a few significant differences between the cohorts and groups related to the background variables (gender, age). The different cohorts were rating the quality of the programs very similarly but some differences between the cohorts were found in the importance and effectiveness ratings. Graduates of 2001 and 2002 rated the importance of the program significantly higher than 2000 graduates. The effectiveness of the programs was rated significantly higher by 2001 and 2003 graduates than other groups. In spite of these individual differences between cohorts there were no linear trends among the year cohorts in any measure. In respondents’ ratings of the effectiveness of teacher education programs there was significant difference between males and females; females rated it higher than males. There were no significant differences between males’ and females’ ratings of the importance and quality of programs. In the ratings there was only one difference between age groups. Older graduates (35 years or older) rated the importance of the teacher training significantly higher that 25-35 years old graduates. In graduates’ ratings there were positive but relatively low correlations between all variables related to importance, effectiveness and quality of Teacher Education Programs. Generally speaking students’ ratings about importance, effectiveness and quality of teacher education program were very positive. There was only one significant difference related to the background variables. Females rated higher the effectiveness of the program. The comparison of students’ and graduates’ perception about importance, effectiveness, and quality of teacher education programs showed that there were no significant differences between graduates and students in the overall ratings. However there were differences in some individual variables. Students rated higher in importance of “Continuous Professional Development”, effectiveness of “Critical Thinking Skills” and “Using Educational Technology” and quality of “Advice received from the advisor”. Graduates rated higher in importance of “Knowledge of Learning Environment” and effectiveness of “Continuous Professional Development”. According to the qualitative data of study 2 some graduates expressed that their perceptions have not changed about the importance, effectiveness, and quality of training that they received during their study time. They pointed out that teacher education programs have provided them the basic theoretical/formal knowledge and some training of practical routines. However, a majority of the teachers seems to have somewhat critical opinions about the teacher education. These teachers were not satisfied with teacher education programs because they argued that the programs failed to meet their practical demands in different everyday situations of the classroom e.g. in coping with students’ learning difficulties, multiprofessional communication with parents and other professional groups (psychologists and social workers), and classroom management problems. Participants also emphasized more practice oriented knowledge of subject matter, evaluation methods and teachers’ rights and responsibilities. Therefore, they (54.1% of participants) suggested that teacher education departments should provide more practice-based courses and programs as well as closer collaboration between regular schools and teacher education departments in order to fill gap between theory and practice.
Resumo:
The target organization of this study, otherwise South-Karelia Social and Health Care District (Eksote) provides health, senior, family and social welfare services. South Karelia Central Hospital provides special health care and offers health services from all of the most important medical specialties. Eksote has in use 15D instrument to measure the health-related quality of life (HRQoL) of their patients before and after their interventions for observing the health effects of the medical care. Furthermore, 15D allows measuring the effectiveness and cost-effectiveness of health care when comparing these before and after results of the 15D measurements and adding the costs of the interventions into this research. The main purposes of this study were to analyze the effectiveness and cost-effectiveness of medical care in South Karelia Central Hospital by using the gathered 15D data to calculate effectiveness and cost-effectiveness ratios and to analyze the reliability and availability of the data. Study has been conducted using literature review and quantitative research methods. The results indicate that from the patients within the eight units selected to this study the 15D change information was available from the 52 %, the 15D change and the cost information from 38 % and the information of quality-adjusted life years (QALYs) produced and the cost information from 35 %. The effectiveness and cost-effectiveness of medical care were greatest at the units of Pain Outpatient Clinic and Rheumatic Diseases Outpatient Clinic. The most effective medical care is given in the unit where the average price of one produced QALY is the highest (Orthopedics). However, the calculated standard deviations pointed out that there are great variances in the effectiveness and cost-effectiveness within the units also.
Resumo:
Tuotekehityksen rooli yrityksen oleellisena menestystekijänä korostuu entistä enemmän alati kovenevassa kilpailussa. Tuotekehityksen tulee toimia entistä tehokkaammin turvatakseen yrityksen menestyminen. Tämän tutkimuksen tavoitteena oli selvittää ja tuoda esiin niitä oleellisia tekijöitä, jotka vaikuttavat metalliteollisuudessa toimivan yrityksen tuotekehityksen suorituskykyyn ja sen tehostamiseen. Tutkimuksen avulla pyrittiin lisäämään informaatiota tuotekehitys- ja yritysjohdon päätöksenteon tueksi. Lisäksi tutkimus antaa tietoa tuotekehityksen suorituskyvyn mittausjärjestelmän suunnittelusta, käyttöönotosta, käytöstä sekä käytetyistä mittausjärjestelmistä ja mittareista. Tuotekehityksen suorituskykyä tarkasteltiin useammasta näkökulmasta. Empiiristä aineistoa koottiin kirjallisuuskatsauksen ja yrityksessä toteutetun kyselyn avulla. Yrityskyselyssä käytettiin neliportaista Likert-skaalaa. Kyselyn tuloksia arvioitiin keskiarvojen ja -hajontojen perusteella. Tutkimuksen tuloksena selvisi, että suorituskyvyn mittauksella ja mittausjärjestelmän avulla voidaan tehostaa tuotekehityksen suorituskykyä. Niitä tärkeitä osa-alueita, joihin tehostamistoimenpiteet tulee kohdistaa, ovat asiakas, henkilöstö, strategia, talous ja mittaamiseen liittyvät tekijät. Yrityksissä piilevänä olevan aineettoman pääoman arvoa ja sen tarjoamaa menestyspotentiaalia ei ole aina tiedostettu.
Resumo:
In this thesis, stepwise titration with hydrochloric acid was used to obtain chemical reactivities and dissolution rates of ground limestones and dolostones of varying geological backgrounds (sedimentary, metamorphic or magmatic). Two different ways of conducting the calculations were used: 1) a first order mathematical model was used to calculate extrapolated initial reactivities (and dissolution rates) at pH 4, and 2) a second order mathematical model was used to acquire integrated mean specific chemical reaction constants (and dissolution rates) at pH 5. The calculations of the reactivities and dissolution rates were based on rate of change of pH and particle size distributions of the sample powders obtained by laser diffraction. The initial dissolution rates at pH 4 were repeatedly higher than previously reported literature values, whereas the dissolution rates at pH 5 were consistent with former observations. Reactivities and dissolution rates varied substantially for dolostones, whereas for limestones and calcareous rocks, the variation can be primarily explained by relatively large sample standard deviations. A list of the dolostone samples in a decreasing order of initial reactivity at pH 4 is: 1) metamorphic dolostones with calcite/dolomite ratio higher than about 6% 2) sedimentary dolostones without calcite 3) metamorphic dolostones with calcite/dolomite ratio lower than about 6% The reactivities and dissolution rates were accompanied by a wide range of experimental techniques to characterise the samples, to reveal how different rocks changed during the dissolution process, and to find out which factors had an influence on their chemical reactivities. An emphasis was put on chemical and morphological changes taking place at the surfaces of the particles via X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM). Supporting chemical information was obtained with X-Ray Fluorescence (XRF) measurements of the samples, and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) measurements of the solutions used in the reactivity experiments. Information on mineral (modal) compositions and their occurrence was provided by X-Ray Diffraction (XRD), Energy Dispersive X-ray analysis (EDX) and studying thin sections with a petrographic microscope. BET (Brunauer, Emmet, Teller) surface areas were determined from nitrogen physisorption data. Factors increasing chemical reactivity of dolostones and calcareous rocks were found to be sedimentary origin, higher calcite concentration and smaller quartz concentration. Also, it is assumed that finer grain size and larger BET surface areas increase the reactivity although no certain correlation was found in this thesis. Atomic concentrations did not correlate with the reactivities. Sedimentary dolostones, unlike metamorphic ones, were found to have porous surface structures after dissolution. In addition, conventional (XPS) and synchrotron based (HRXPS) X-ray Photoelectron Spectroscopy were used to study bonding environments on calcite and dolomite surfaces. Both samples are insulators, which is why neutralisation measures such as electron flood gun and a conductive mask were used. Surface core level shifts of 0.7 ± 0.1 eV for Ca 2p spectrum of calcite and 0.75 ± 0.05 eV for Mg 2p and Ca 3s spectra of dolomite were obtained. Some satellite features of Ca 2p, C 1s and O 1s spectra have been suggested to be bulk plasmons. The origin of carbide bonds was suggested to be beam assisted interaction with hydrocarbons found on the surface. The results presented in this thesis are of particular importance for choosing raw materials for wet Flue Gas Desulphurisation (FGD) and construction industry. Wet FGD benefits from high reactivity, whereas construction industry can take advantage of slow reactivity of carbonate rocks often used in the facades of fine buildings. Information on chemical bonding environments may help to create more accurate models for water-rock interactions of carbonates.
Resumo:
Kandidaatintyö tehtiin osana PulpVision-tutkimusprojektia, jonka tarkoituksena on kehittää kuvapohjaisia laskenta- ja luokittelumetodeja sellun laaduntarkkailuun paperin valmistuksessa. Tämän tutkimusprojektin osana on aiemmin kehitetty metodi, jolla etsittiin kaarevia rakenteita kuvista, ja tätä metodia hyödynnettiin kuitujen etsintään kuvista. Tätä metodia käytettiin lähtökohtana kandidaatintyölle. Työn tarkoituksena oli tutkia, voidaanko erilaisista kuitukuvista laskettujen piirteiden avulla tunnistaa kuvassa olevien kuitujen laji. Näissä kuitukuvissa oli kuituja neljästä eri puulajista ja yhdestä kasvista. Nämä lajit olivat akasia, koivu, mänty, eukalyptus ja vehnä. Jokaisesta lajista valittiin 100 kuitukuvaa ja nämä kuvat jaettiin kahteen ryhmään, joista ensimmäistä käytettiin opetusryhmänä ja toista testausryhmänä. Opetusryhmän avulla jokaiselle kuitulajille laskettiin näitä kuvaavia piirteitä, joiden avulla pyrittiin tunnistamaan testausryhmän kuvissa olevat kuitulajit. Nämä kuvat oli tuottanut CEMIS-Oulu (Center for Measurement and Information Systems), joka on mittaustekniikkaan keskittynyt yksikkö Oulun yliopistossa. Yksittäiselle opetusryhmän kuitukuvalle laskettiin keskiarvot ja keskihajonnat kolmesta eri piirteestä, jotka olivat pituus, leveys ja kaarevuus. Lisäksi laskettiin, kuinka monta kuitua kuvasta löydettiin. Näiden piirteiden eri yhdistelmien avulla testattiin tunnistamisen tarkkuutta käyttämällä k:n lähimmän naapurin menetelmää ja Naiivi Bayes -luokitinta testausryhmän kuville. Testeistä saatiin lupaavia tuloksia muun muassa pituuden ja leveyden keskiarvoja käytettäessä saavutettiin jopa noin 98 %:n tarkkuus molemmilla algoritmeilla. Tunnistuksessa kuitujen keskimäärinen pituus vaikutti olevan kuitukuvia parhaiten kuvaava piirre. Käytettyjen algoritmien välillä ei ollut suurta vaihtelua tarkkuudessa. Testeissä saatujen tulosten perusteella voidaan todeta, että kuitukuvien tunnistaminen on mahdollista. Testien perusteella kuitukuvista tarvitsee laskea vain kaksi piirrettä, joilla kuidut voidaan tunnistaa tarkasti. Käytetyt lajittelualgoritmit olivat hyvin yksinkertaisia, mutta ne toimivat testeissä hyvin.