831 resultados para Exploratory Factor Analysis


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In this paper we set out a confirmatory factor analysis model relating the values adolescents and their parents aspire to for the child’s future. We approach a problem when collecting parents’ answers and analysing paired data from parents and their child: the fact that in some families only one parent answers, while in others both meet to answer together. In order to account for differences between one-parent and two-parent responses we follow a multiple group structural equation modelling approach. Some significant differences emerged between the two and one answering parent groups. We observed only weak relationships between parents’ and children’s values

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One hundred fifteen cachaça samples derived from distillation in copper stills (73) or in stainless steels (42) were analyzed for thirty five itens by chromatography and inductively coupled plasma optical emission spectrometry. The analytical data were treated through Factor Analysis (FA), Partial Least Square Discriminant Analysis (PLS-DA) and Quadratic Discriminant Analysis (QDA). The FA explained 66.0% of the database variance. PLS-DA showed that it is possible to distinguish between the two groups of cachaças with 52.8% of the database variance. QDA was used to build up a classification model using acetaldehyde, ethyl carbamate, isobutyl alcohol, benzaldehyde, acetic acid and formaldehyde as chemical descriptors. The model presented 91.7% of accuracy on predicting the apparatus in which unknown samples were distilled.

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Aerosol size distributions from 6 to 700 nm were measured simultaneously at an urban background site and a roadside station in Oporto. The particle number concentration was higher at the traffic exposed site, where up to 90% of the size spectrum was dominated by the nucleation mode. Larger aerosol mode diameters were observed in the urban background site possibly due to the coagulation processes or uptake of gases during transport. Factor analysis has shown that road traffic and the neighbour stationary sources localised upwind affect the urban area thought intra-regional pollutant transport.

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A study on the monitoring of glycerol oxidation catalyzed by gold nanoparticles supported on activated carbon under mild conditions by chemometric methods is presented. The reaction was monitored by mass spectrometry-electrospray ionization (ESI-MS) and comparatively by mid infrared spectroscopy (MIR). Concentration profiles of reagent and products were determined by chemometric tools such as Principal Component Analysis (PCA), Evolving Factor Analysis (EFA) and Multivariate Curve Resolution (MCR). The gold nanoparticle catalyst was relatively active in glycerol oxidation, favoring formation of high added value products. It was found that the reaction stabilization was reached at four hours, with approximately 70% glycerol conversion and high selectivity for glycerate.

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Kirjallisuusarvostelu

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The processes and sources that regulate the elemental composition of aerosol particles were investigated in both fine and coarse modes during the dry and wet seasons. One hundred and nine samples were collected from the biological reserve Cuieiras - Manaus from February to October 2008, and analyzed together with 668 samples that were previously collected at Balbina from 1998 to 2002. Particle induced X-ray emission technique was used to determine the elemental composition, while the concentration of black carbon was obtained from the measurement of optical reflectance. Absolute principal factor analysis and positive matrix factorization were performed for source apportionment, which was complemented with back trajectory analysis. A regional identity for the natural biogenic aerosol was found for the Central Amazon Basin and can be used in dynamical chemical region models.

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The objective of this work was to develop a free access exploratory data analysis software application for academic use that is easy to install and can be handled without user-level programming due to extensive use of chemometrics and its association with applications that require purchased licenses or routines. The developed software, called Chemostat, employs Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), intervals Principal Component Analysis (iPCA), as well as correction methods, data transformation and outlier detection. The data can be imported from the clipboard, text files, ASCII or FT-IR Perkin-Elmer “.sp” files. It generates a variety of charts and tables that allow the analysis of results that can be exported in several formats. The main features of the software were tested using midinfrared and near-infrared spectra in vegetable oils and digital images obtained from different types of commercial diesel. In order to validate the software results, the same sets of data were analyzed using Matlab© and the results in both applications matched in various combinations. In addition to the desktop version, the reuse of algorithms allowed an online version to be provided that offers a unique experience on the web. Both applications are available in English.

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The calyxes of Hibiscus sabdariffa are used in traditional medicine around the world. However, quality assurance protocols and chemical variability have not been previously analyzed. In the present study, chemical characterization of a set of samples of H. sabdariffa calyxes commercialized in Colombia was accomplished with the aim to explore the chemical variability among them. Chemometrics-based analyses on the data obtained from the HPLC-UV-DAD-derived profiles were then performed. Thus, the pre-processed single-wavelength data were subjected to principal component analysis (PCA). The PCA-derived results evidenced different groups which were well-correlated to the corresponding total phenolic and total anthocyanin contents. Multi-wavelength chromatographic (HPLC-UV-DAD surfaces) data were additionally examined via parallel factor analysis (PARAFAC) as data reduction method and the obtained loadings were subsequently submitted to PCA and orthogonal partial least squares discriminant analysis (OPLS-DA). Results were thus consistent with those from single-wavelength data. PCA loadings were employed to determine those chemical components responsible for the data variance and OPLS-DA model, constructed from PARAFAC loadings, and indicated differentiation according total anthocyanin contents among samples. The present chemometric analysis therefore demonstrated to be an excellent tool for differentiation of H. sabdariffacalyxes according to their chemical composition.

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Although social capital and health have been extensively studied during the last decade, there are still open issues in current empirical research. These concern for instance the measurement of the concept in different contexts, as well as the association between different types of social capital and different dimensions of health. The present thesis addressed these questions. The general aim was to promote the understanding of social capital and health by investigating the oldest old and the two major language groups in Finland, Swedish- and Finnish-speakers. Another aim was to contribute to the discussion on methodological issues in social capital and health research. The present thesis investigated two empirical data sets, Umeå 85+ and Health 2000. The Umeå 85+ study was a cross-sectional study of 163 individuals aged 85, 90, and 95 or older, living in the municipality of Umeå, Sweden, in the year of 2000. The Health 2000 survey was a national study of 8,028 persons aged 30 or above carried out in Finland in 2000-2001. Different indicators of structural (e.g. social contacts) and cognitive (e.g. trust) social capital, as well as health indicators were used as variables in the analyses. The Umeå 85+ data set was analyzed with factor analysis, as well as univariate and multivariate analysis of variance. The Health 2000 data was analyzed with logistic regression techniques. The results showed that the Swedish-speakers in the Finnish data set Health 2000 had consistently higher prevalence of social capital compared to the Finnish-speakers even after controlling for central sociodemographic variables. The results further showed that even if the language group differences in health were small, the Swedishspeakers experienced in general better self-reported health compared with the Finnish-speakers. Common sociodemographic variables could not explain these observed differences in health. The results imply that social capital is often, but not always, associated with health. This was clearly seen in the Umeå 85+ data set where only one health indicator (depressive symptoms) was associated with structural social capital among the oldest old. The results based on the analysis of the Health 2000 survey demonstrated that the cognitive component of social capital was associated with self-rated health and psychological health rather than with participation in social activities and social contacts. In addition, social capital statistically reduced the health advantage especially for Swedish-speaking men, indicating that high prevalence of social capital may promote health. Finally, the present thesis also discussed the issue of methodological challenges faced with when analyzing social capital and health. It was suggested that certain components of social capital such as bonding and bridging social capital may be more relevant than structural and cognitive components when investigating social capital among the two language groups in Finland. The results concerning the oldest old indicated that the structural aspects of social capital probably reflect current living conditions, whereas cognitive social capital reflects attitudes and traits often acquired decades earlier. This is interpreted as an indication of the fact that structural and cognitive social capital are closely related yet empirically two distinctive concepts. Taken together, some components of social capital may be more relevant to study than others depending on which population group and age group is under study. The results also implied that the choice of cut-off point of dichotomization of selfrated health has an impact on the estimated effects of the explanatory variables. When the whole age interval, 35-64 years, was analyzed with logistic regression techniques the choice of cut-off point did not matter for the estimated effects of marital status and educational level. The results changed, however, when the age interval was divided into three shorter intervals. If self-rated health is explored using wide age intervals that do not account for age-dependent covariates there is a risk of drawing misleading conclusions. In conclusion, the results presented in the thesis suggest that the uneven distribution of social capital observed between the two language groups in Finland are of importance when trying to further understand health inequalities that exist between Swedish- and Finnish-speakers in Finland. Although social capital seemed to be relevant to the understanding of health among the oldest old, the meaning of social capital is probably different compared to a less vulnerable age group. This should be noticed in future empirical research. In the present thesis, it was shown that the relationship between social capital and health is complex and multidimensional. Different aspects of social capital seem to be important for different aspects of health. This reduces the possibility to generalize the results and to recommend general policy implementations in this area. An increased methodological awareness regarding social capital as well as health are called for in order to further understand the cfomplex association between them. However, based on the present data and findings social capital is associated with health. To understand individual health one must also consider social aspects of the individuals’ environment such as social capital.

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Tutkimuksen päätarkoituksena on selvittää lukio-opiskelijoiden käsityksiä oppimisensa itsesäätelystrategioista. Lukiokoulutuksessa toteutetut muutokset kuten valinnanmahdollisuuksien lisääntyminen ovat antaneet lukio-opiskelijoille kasvaneen mahdollisuuden omanlaisensa lukio-opiskelupolun suunnitteluun ja yksilölliseen tavoitteenasetteluun. Työssä tarkastellaan myös lukio-opiskelijoiden opintojen kulkua, erilaisia opiskeluodotuksia ja niiden toteutumista sekä näiden yhteyttä itsesäätelyyn. Tutkimus toteutettiin seurantatutkimuksena, jossa kyselylomakkeilla kerättiin tietoa syksyllä 2004 Turun kaupungin suomenkielisissä päivälukioissa (10 koulua) opintonsa aloittavilta opiskelijoilta kahdesti; ensimmäisenä ja kolmantena opiskeluvuotena. Tutkimuksessa oli mukana 245 opiskelijaa, 142 tyttöä ja 103 poikaa. Tutkimuksen vastausprosentti oli 84 %. Kyselylomakkeiden itsesäätelyä ja oppimisorientaatioita koskevat kysymykset pohjautuivat Jan Vermuntin ILS-oppimistyylimittariin (Inventory of Learning Styles) (Vermunt 1994; 1996). Lisäksi haastateltiin 15 tutkimuksessa mukana ollutta opiskelijaa. Kyselylomakeaineisto analysoitiin ristiintaulukoinneilla, korrelaatiokertoimilla, t-testeillä ja erilaisilla varianssianalyyseillä. Itsesäätelystrategiamittarin neljän summamuuttujan oletus testattiin erikseen mittauksissa 1 ja 2 konfirmatorisen faktorianalyysin avulla. Tutkimuksessa identifioitiin klusterianalyysillä tehdyssä ryhmittelyssä neljä erilaista lukio-opiskelijaryhmää: menestyvät navigoijat, tavalliset tasapainoilijat, säätelemättömät kulkeutujat ja ylikuormittuneet avuntarvitsijat. Navigoijille on tyypillistä niin prosessin/ tulosten kuin sisällön suhteen korkea itsesäätely. Tyypillinen piirre navigoijien kohdalla on myös ulkoisen säätelyn korkea taso. Avuntarvitsijat eroavat muista ryhmistä selkeästi korkeampien puutteellisten säätelystrategioidensa perusteella, vaikka heidän itsesäätelynsä on suhteellisesti niihin ja muihin ryhmiin nähden melko korkealla tasolla. Tasapainoilijat sijoittuvat itsesäätelyn ja ulkoisen säätelyn osalta ryhmien keskitasolle. Kulkeutujien itsesäätely samoin kuin ulkoinen säätely ovat ryhmien matalinta tasoa. Tuloksista nähdään, että kehittyneemmällä itsesäätelyllä on selvä yhteys lukio-opintojen sujuvuuteen ja opintomenestykseen, mutta noin kolmasosalle opiskelijoista itsesäätelevä, suunnitelmallinen tavoitteenasettelu on vaikeaa. Navigoijilla ja tasapainoilijoilla opiskelu on sekä heille itselleen mielekästä että ulkoisesti arvioituna tehokasta. Joidenkin opiskelijoiden erityisesti avuntarvitsijoiden ja kulkeutujien keskuudessa opintojen kulku sen sijaan hapuilee. Lukiolaisten opiskeluun kohdistuvien odotusten voidaan tämän tutkimuksen tuloksen perusteella katsoa ennustavan todellista opintojen kulkua ja opintomenestystä melko hyvin. Eroja on sekä tavoitetasossa, opiskeluprosessiin liittyvissä kokemuksissa että jatko-opintosuunnitelmissa ja ne ovat yhteydessä sukupuoleen, isän sosioekonomiseen asemaan, erikoislinjalla opiskeluun sekä lukion alun itsesäätelyryhmiin.

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This research establishes the primary components, predictors, and consequences of organizational commitment in the military context. Specifically, the research examines commitment to the military service among Finnish conscripts and whether initial affective commitment prior to service predicts later commitment, attitudes, behavior, and performance, and, furthermore, analyzes the changes in commitment and its possible outcomes. The data were collected from records as well as by surveys from 1,387 rank and file soldiers, immediately after they reported for duty, near the end of basic training, and near the end of 6 to 12 months of service. The data covered a wide array of predictor variables, including background items, attitudes toward conscription, mental and physical health, sociability, training quality, and leadership. Moreover, the archival data included such items as rank, criminal record, performance ratings, and the number of medical examines and exemptions. The measures were further refined based on the results of factor analysis and reliability tests. The results indicated that initial commitment significantly corresponded with expected adjustment, intentions to stay in the military, and acceptance of authority. Moreover, initial commitment moderately related to personal growth, perceived performance, and the number of effective service days at the end of service. During basic training, affective commitment was mostly influenced by challenging training, adjustment experiences, regimentation, and unit climate. At the end of service, committed soldiers demonstrated more personal growth and development in service, had higher-level expected performance, and less malingering during their service. Additionally, they had significantly more positive attitudes toward national defense. The results suggest that affective commitment requires adequate personal adjustment, experiences of personal growth and development, and satisfaction with unit dynamics and training. This research contributes to the theoretical discussion on organizational commitment and the will to defend the nation and advances developing models to support and manage conscript training, education, leadership, and personnel policy. This is achieved by determining the main factors and variables, including their relative strength, that affect commitment to the military service. These findings may also facilitate in designing programs aimed at reducing unwanted discharges and inadequate performance. In particular, these results provide tools for improving conscripts’ overall attachment to and identification with the military service.

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The main objective of this Master’s Thesis was to examine the interrelations of service quality and relationship quality (customer satisfaction, trust and commitment), and find out are they antecedents for customer loyalty in business-to-business context. Literature review revealed some research gaps concerning these focal concepts, which should be studied more closely. The theoretical basis for this research was collected for evaluating a strategic increase of customer’s perceptions of service quality and relationship quality as well as customer loyalty in business-to-business environment, and it was tested empirically in a sample of 164 corporate customers, who responded to the Internet-based survey. The measures, used in the survey, were first assessed by using confirmatory factor analysis (CFA), and then the hypothesized relationships were further verified using structural equation modeling (SEM) in LISREL 8.80. There was found support for a half of the hypothesized construct relations. The results of the research confirm the direct influence of trust and commitment on customer loyalty. Also, service quality turned out to have an indirect impact on customer loyalty through trust. No support, however, was offered for the proposed impact of customer satisfaction on loyalty in this case. The research provides managerially relevant and actionable results that may help service providers execute more specific customer relationship quality strategies that lead to higher customer loyalty.

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The intent of this research was to develop a model that describes the extent to which customer behavioral intentions are influenced by service quality, customer satisfaction and customer perceived value in the business-to-business service context. Research on customer behavioral intentions is quite fragmented and no generalized model has been presented. Thus, there was need for empirical testing. This study builds on the services marketing theory and assesses the relationships between the identified constructs. The data for the empirical analysis was collected via a quantitative online survey and a total of 226 usable responses were obtained for further analysis. The model was tested in an employment agency service setting. The measures used in this survey were first assessed by using confirmatory factor analysis (CFA) after which the hypothesized relationships were further verified using structural equation modeling (SEM) in LISREL 8.80. The analysis identified that customer satisfaction played a pivotal role in the model as it was the only direct antecedent of customer behavioral intentions, however, customer perceived value showed a strong indirect impact on buying intentions via customer satisfaction. In contrast to what was hypothesized, service quality and customer perceived value did not have a direct positive effect on behavioral intentions. Also, a contradicting finding with current literature was that sacrifice was argued to have a direct but positive impact on customer perceived value. Based on the findings in this study, managers should carefully think of their service strategies that lead to their customers’ favorable behavioral intentions.

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Tutkielman tarkoitus oli selvittää, mitkä tekijät määrittelevät kansainvälistymisprosessin potentiaalista menestyjää. Aihetta on tutkittu paljon, mutta laajempi kokonaiskuva kansainvälistymisen menestystekijöistä puuttui. Tutkielman näkökulma on holistinen: Siinä yhdistettiin useampi linssi eri näkökulmia menestymiseen kansainvälistymisessä ja eri tutkimusmetodeja kvalitatiivisista kvantitatiivisiin. Tutkimuksessa käytettiin teoriasidonnaista lähestymistapaa ja konstruktiivista tutkimusotetta, jonka avulla Finpro ry:lle rakennettiin usean tutkimusvaiheen aikana potentiaalisia menestystapauksia tunnistava työkalu. Tutkimus toteutettiin neljässä vaiheessa, joissa rakennettiin kunkin vaiheen testituloksien mukainen konstruktio. Ensimmäisessä vaiheessa teemahaastattelulla selvitettiin konstruktion tarvepohja sekä rajaehdot. Konstruktion pohjaksi taulukoitiin 2001–2012 vuosien tutkimuksien tutkituimmat menestystekijät ja siihen lisättiin kansainvälistymisprosessin asiantuntijoiden korostamat menestystekijät. Tulokset yhdistettiin rakentamalla Konstruktio1. Toisessa vaiheessa Konstruktio1:sta kyselyn ja eksploratiivisen faktorianalyysin avulla faktoroitiin tärkeimmät menestymisen taustalla olevat ilmiöt, joista rakennettiin Konstruktio2. Kolmannessa vaiheessa kahden riippumattomien otosten ttestin avulla selvitettiin, mitkä Konstruktio2:n menestysfaktorit ovat tärkeimpiä ICT- ja life science -toimialoilla toimiville yrityksille ja mitä ilmiöitä yrityksen johto tai sijoittajat pitävät tärkeinä. Tuloksien pohjalta Konstruktio2 kehitettiin Konstruktio3:ksi. Neljännessä vaiheessa Konstruktio3:n pätevyyttä testattiin peilaamalla sen menestysfaktoreita kuuteen menestyjiksi todettuun tapaukseen, ja sen toimivuus selvitettiin kuuden avoimen haastattelun avulla. Tuloksien avulla Konstruktio3:sta rakennettiin Konstruktio4. Tutkimukset osoittivat, että menestystekijät vaihtelevat yrityksen kansainvälistymispolun ja eri näkökulmien mukaan. Tutkimus loi vahvan teoreettisen ja liiketoiminnallisen kontribuution. Tutkimusvaiheiden avulla hahmotettiin kansainvälistymisessä menestymisen kokonaisuus ja luottiin uusi näkemys pk-yrityksen menestymisestä. Toisaalta päästiin myös heti käyttövalmiiseen lopputulokseen, joka auttaa Finpron konsultteja ja myyjiä ymmärtämään menestymistä kansainvälistymisprosessissa ja löytämään potentiaalisia menestyjiä.

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Riskit ja riskittömyys uhkaavat yksilöitä, käsityötä ja yhteiskuntaa. Käsityökasvatukselleon haaste toimia kulttuurissa, joka tavoittelee täyttä riskittömyyttä. Käsityössä kasvatetaan kekseliäisyyteen ja varautumaan sen aiheuttaman riskin kohtaamiseen sekä ottamaan siitä vastuuta. Tämän tutkimuksen tehtävänä on riskivastuullisuuden mallin rakentamiseksi selvittää, kuinka oppilaiden vastuullisuus selittää riskirajaa käsityön turvallisuuskasvatuksen kulttuurissa. Välinearvojen saavuttamiseksi on siedettävä välineriskiä, joka ei ylitä turvallisuuskulttuurin riskirajaa. Välinearvot ovat välineiden laatua lisääviä ominaisuuksia, joilla pyritään peittämään välineriskejä. Siedettävän riskin rajan ratkaisemiseen tarvitaan tietoa käsityön tuottamisesta ja todellisuutta havainnoivien tiedonalojen tietoa. Viime kädessä ratkaisu tehdään rakentavalla ajattelulla, johon kuuluu välinearvojen tavoittelua ohjaava käsityötaju ja välineriskeihin varautumista ohjaava turvallisuustaju. Käsityössä onnistuminen kannustaa kohti uusia haasteita ja epäonnistumisen riski asettuu mittasuhteisiinsa. Kekseliäässä käsityön kulttuurissa kokeillaan omia ja ympäröivän todellisuuden mahdollisuuksia ottamalla oivaltaen riskejä, jotka saavat aikaan rakentavan kokemuksen riskistä. Käsityö on riskioivallusten oppiaine. Tutkimustehtävän toteuttamiseksi tässä tutkimuksessa rakennetaan uusi riskivastuullisuuden malli, jossa vastuullisuus selittää riskirajaa. Mallin vastaavuutta selvitetään valtakunnallisesti peruskoulun käsityön 6. ja 9. luokan käsityön opetuksessa (n = 393). Aineisto on analysoitu rakenneyhtälöanalyysein konfirmatorisella faktorianalyysilla ja polkumallinnuksella. Tutkimusaineisto ja riskivastuullisuuden malli vastaavat toisiaan. Vastuullisuuden selitysosuus turvallisuustajun ja käsityötajun ratkaisemasta riskirajasta on mallin mukaan 35 %. Oppilaat osoittivat tuntevansa oman tuottamisensa vaikutuksia ja vastuuta niistä. Vastuullisuus osoittautui tärkeäksi riskirajan selittäjäksi, joten käsityön turvallisuuskasvatuksen kulttuuri voi kohota uudelle tasolle riskivastuulliseksi. Käsityön turvallisuuskasvatus on kokonaisvaltaista turvallisuustajun kasvatusta. Riskivastuullisuus luo turvallisuuskulttuuriin yhteisen käsityksen siedettävän riskin rajasta. Oppilaiden mahdollisuuksia kekseliääseen tutkivaan tuottamiseen on vahvistettava eikä rajoitettava. Riskivastuullisessa käsityön turvallisuuskasvatuksen kulttuurissa opettajan tehtävänä ei ole estää mitään tapahtumasta vaan saada mahdollisimman paljon tapahtumaan, sillä vastuullisuus kasvaa vastuuta ottamalla. Se on kasvatuksen – käsityökasvatuksen – keino turvallisuustyössä.