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Avaliação do uso do pensamento estatístico e técnicas estatísticas em empresas de bens de capital seriados do Estado de São PauloCarvalho, Nelio Garbellini de 16 October 2015 (has links)
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Previous issue date: 2015-10-16 / Não recebi financiamento / With more advanced marketing relations, various changes are taking place in regard to
competitive factor markets, among which, the importance of quality processes and goods
supplied to the society, stand out. Therefore, diverse programs and methods have been
developed to monitor indicators of production processes and the characteristics of roduct
quality, many of which are supported by statistical concepts. This process encourages
understanding and the use of Statistical Thinking (ST), Statistical Engineering (SE), and
Statistical Techniques (STe) in businesses, highlighting their importance to quality
management and the efficiency of organizational processes. This thesis’s aim was to analyze the use of ST and STe in a sample of industries in the sector of serial capital goods located in the state of São Paulo, Brazil. For that, an exploratory-descriptive survey was conducted with 42 medium and large companies from different segments of the sector. Data were statistically analyzed using descriptive and multivariate methods (cluster analysis, association and correlation). These analyses revealed there is considerable space to diffuse Statistical Thinking and Statistical Techniques in these companies, as well as revealed a lack of training in statistical principles and techniques, the main obstacles to the systematic application of these techniques, and the lack of support on the part of top management. There is evidence that the successful implementation of Total Quality Management (TQM) and Total Productive Maintenance in the industries of sector significantly influences the diffusion of ST and the application of STe; while the use of Six Sigma program especially impacts the application of more complex STe; and ST has the potential to promote the application of STe. / Com a evolução das relações mercadológicas, diversas mudanças vêm ocorrendo a respeito
dos fatores competitivos do mercado, dentre os quais se destaca a importância da qualidade
dos processos e produtos disponibilizados à sociedade. Dessa maneira, diversos programas e métodos têm sido desenvolvidos com o objetivo de acompanhar os indicadores dos processos produtivos e monitorar as características da qualidade do produto, utilizando para isso técnicas, muitas delas suportadas por conceitos estatísticos, o que, consequentemente, estimula a compreensão e uso do Pensamento Estatístico (PE), da Engenharia Estatística (EE) e das Técnicas Estatísticas (TE) nas empresas e destaca sua importância para a gestão da qualidade e eficiência de processos organizacionais. Essa dissertação tem por objetivo analisar o uso do PE e de TE em uma amostra de empresas industriais do setor de bens de capital seriados, localizadas no estado de São Paulo. Para isso, foi conduzida uma survey exploratória-descritiva em 42 empresas de médio e grande porte de diferentes segmentos do setor. Os dados obtidos foram analisados estatisticamente por métodos descritivos e multivariados (análise de cluster, associação e correlação). Tais análises revelaram a existência de um grande espaço para difusão do Pensamento Estatístico e das Técnicas Estatísticas nessas empresas, bem como a ausência de treinamentos em princípios e técnicas estatísticas, os principais obstáculos para a aplicação sistemática dessas técnicas e a falta de suporte da alta administração. Há evidências de que a implantação bem-sucedida dos programas TQM (Total Quality Management) e TPM (Total Productive Maintenance) nas empresas o setor exerceu significativa influência sobre a difusão do PE e aplicação das TE; de que o Programa Seis Sigma impacta especialmente na aplicação das TE de maior complexidade; e de que o uso do PE tem potencial para promover maior aplicação das TE.
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The psychological health implications of social support for the Alzheimer caregiverCoetsee, Martha Johanna 25 August 2008 (has links)
Apart from the personal and socioeconomic burdens of dementia, the immense, intangible emotional and psychological suffering endured by dementia patients, their carers and families are difficult to quantify. Alzheimer’s dementia (AD) accounts for over 50% of all dementias and is responsible for a large percentage of morbidity and mortality in older adults. It is also recognised as a disease qualitatively distinct from the normal ageing process. Identified almost 95 years ago by Alois Alzheimer, it poses a seminal problem, which in the twenty-first century is compounded by the predicted extension in human longevity. Caregivers thus bear a considerable financial, social and emotional burden due to the progressive debilitating nature of the disease. It is hypothesised that social support buffers the individual from the negative emotional effects of stressful circumstances associated with the caregiving process; and although the inevitable course of the disease cannot be stopped, improving support to caregivers may decrease feelings of isolation and improve psychological health. Caregivers of AD patients often report experiencing a lack of social support due to the nature and progression of this disease. This study thus aims to investigate the relationship between real and/or perceived social support and psychological health (depression, loneliness, and perceived burden of care) amongst a cohort of Alzheimer’s caregivers. The following standardised measuring instruments were used to elicit data: the Zarit Burden Interview (ZBI), the Beck Depression Inventory (BDI-II), UCLA Loneliness Scale, Personal Resource Questionnaire (PRQ85) and a biographical questionnaire. Data were analysed using correlation and regression statistical techniques. The main findings of this study were that there is a significant positive correlation between loneliness and depression; loneliness and personal strain (burden) as well as both role and personal strain (burden) with depression. A significant negative correlation was also found between perceived social support and loneliness. Additional findings were that participants with higher educational qualifications experienced more personal strain and role strain (burden); caregivers with patients in the two younger age groups scored higher on the BDI-II; and the cognitive status of the patient correlated with the burden experienced by the caregiver. A significant negative correlation between summaries of reactions (burden) and duration of caregiving was also reported. / Dissertation (MA)--University of Pretoria, 2008. / Psychology / unrestricted
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Structural equation modellingMohanlal, Pramod 06 1900 (has links)
Over the past two decades there has been an upsurge in interest in structural equation
modelling (SEM). Applications abound in the social sciences and econometrics, but
the use of this multivariate technique is not so common in public health research.
This dissertation discusses the methodology, the criticisms and practical problems of
SEM. We examine actual applications of SEM in public health research.
Comparisons are made between multiple regression and SEM and between factor
analysis and SEM. A complex model investigating the utilization of antenatal care
services (ANC) by migrant women in Belgium is analysed using SEM. The
dissertation concludes with a discussion of the results found and on the use of SEM
in public health research. Structural equation modelling is recommended as a tool for
public health researchers with a warning against using the technique too casually. / Mathematical Sciences / M. Sc. (Statistics)
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Searches for Particle Dark Matter : Dark stars, dark galaxies, dark halos and global supersymmetric fitsScott, Pat January 2010 (has links)
The identity of dark matter is one of the key outstanding problems in both particle and astrophysics. In this thesis, I describe a number of complementary searches for particle dark matter. I discuss how the impact of dark matter on stars can constrain its interaction with nuclei, focussing on main sequence stars close to the Galactic Centre, and on the first stars as seen through the upcoming James Webb Space Telescope. The mass and annihilation cross-section of dark matter particles can be probed with searches for gamma rays produced in astronomical targets. Dwarf galaxies and ultracompact, primordially-produced dark matter minihalos turn out to be especially promising in this respect. I illustrate how the results of these searches can be combined with constraints from accelerators and cosmology to produce a single global fit to all available data. Global fits in supersymmetry turn out to be quite technically demanding, even with the simplest predictive models and the addition of complementary data from a bevy of astronomical and terrestrial experiments; I show how genetic algorithms can help in overcoming these challenges. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Accepted. Paper 6: Submitted.
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Supersymmetry vis-à-vis Observation : Dark Matter Constraints, Global Fits and Statistical IssuesAkrami, Yashar January 2011 (has links)
Weak-scale supersymmetry is one of the most favoured theories beyond the Standard Model of particle physics that elegantly solves various theoretical and observational problems in both particle physics and cosmology. In this thesis, I describe the theoretical foundations of supersymmetry, issues that it can address and concrete supersymmetric models that are widely used in phenomenological studies. I discuss how the predictions of supersymmetric models may be compared with observational data from both colliders and cosmology. I show why constraints on supersymmetric parameters by direct and indirect searches of particle dark matter are of particular interest in this respect. Gamma-ray observations of astrophysical sources, in particular dwarf spheroidal galaxies, by the Fermi satellite, and recording nuclear recoil events and energies by future ton-scale direct detection experiments are shown to provide powerful tools in searches for supersymmetric dark matter and estimating supersymmetric parameters. I discuss some major statistical issues in supersymmetric global fits to experimental data. In particular, I further demonstrate that existing advanced scanning techniques may fail in correctly mapping the statistical properties of the parameter spaces even for the simplest supersymmetric models. Complementary scanning methods based on Genetic Algorithms are proposed. / At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.
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Structural equation modellingMohanlal, Pramod 06 1900 (has links)
Over the past two decades there has been an upsurge in interest in structural equation
modelling (SEM). Applications abound in the social sciences and econometrics, but
the use of this multivariate technique is not so common in public health research.
This dissertation discusses the methodology, the criticisms and practical problems of
SEM. We examine actual applications of SEM in public health research.
Comparisons are made between multiple regression and SEM and between factor
analysis and SEM. A complex model investigating the utilization of antenatal care
services (ANC) by migrant women in Belgium is analysed using SEM. The
dissertation concludes with a discussion of the results found and on the use of SEM
in public health research. Structural equation modelling is recommended as a tool for
public health researchers with a warning against using the technique too casually. / Mathematical Sciences / M. Sc. (Statistics)
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BENESSERE FINANZIARIO DEI GIOVANI ADULTI: QUALI METODOLOGIE DI RICERCA E TECNICHE STATISTICHE SONO NECESSARIE? / EMERGING ADULTS' FINANCIAL WELL-BEING: WHAT RESEARCH METHODOLOGIES AND STATISTICAL TECHNIQUES ARE NEEDED?SORGENTE, ANGELA 23 February 2018 (has links)
Lo scopo generale della presente tesi è quello di arricchire la letteratura sul benessere finanziario dei giovani adulti adottando metodologie di ricerca e tecniche statistiche mai applicate in questo filone di ricerca. Nello specifico, nel primo capitolo è stata utilizzata la scoping methodology, ovvero una metodologia di sintesi della letteratura, con l’obiettivo di identificare la definizione, le componenti, i predittori e gli outcome del benessere finanziario dei giovani. Nel secondo capitolo è stata applicata la Latent Transition Analysis, con l’obiettivo di identificare sottogruppi omogenei di giovani rispetto ai marcatori dell’adultità che essi hanno già raggiunto e di verificare la relazione di tali sottogruppi con il benessere finanziario dei giovani che ad essi appartengono. Il terzo capitolo propone una metodologia per sviluppare e validare nuovi strumenti di misurazione, sulla base della visione contemporanea della validità. Tale metodologia, composta da tre diversi step, è stata utilizzata per la creazione di uno strumento adatto a misurare, su un campione di giovani italiani, il benessere finanziario soggettivo. Infine, il quarto capitolo riguarda la multiple informant methodology, che è stata utilizzata per raccogliere informazioni da madre, padre e figlio sul processo di socializzazione finanziaria familiare ed il suo impatto sul benessere finanziario del figlio. / The general aim of this research work is to enrich the literature on emerging adults’ financial well-being with research methodologies and statistical techniques never previously applied in this research field. Specifically, the first chapter of this thesis concerns the scoping methodology, a knowledge synthesis methodology that I adopted to identify the emerging adults’ financial well-being definition, components, predictors and outcomes. The second chapter consists in the application of a new statistical technique, Latent Transition Analysis, that I used to identify subgroups of emerging adults homogeneous in their configuration of adult social markers already reached and to investigate the relation between these emerging adults’ subgroups and their financial well-being. The third chapter describes a three-step methodology to develop and validate new measurement instruments, based on the contemporary view of validity proposed in the last fifty years. This three-step procedure was here applied to develop and validate a new instrument measuring subjective financial well-being for an emerging adult target population. Finally, the fourth chapter concerns the multiple informant methodology that I applied to collect information about family financial socialization and its impact on the child’s financial well-being from mother, father and the emerging adult child.
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Development of evaluation method for visual design with multivariate statistical techniques / Ανάπτυξη μεθόδου αξιολόγησης του σχεδιασμού διεπιφάνειας χρήστη με πολυπαραμετρικές στατιστικές τεχνικέςΠαπαχρήστος, Ελευθέριος 14 October 2013 (has links)
The main goal of this thesis is to propose an evaluation method for visual interface design and more specifically for website design. The proposed visual design evaluation method is an adaptation of Preference Mapping (PM) techniques. It is based on overall preference ratings after multiple comparisons of alternative designs and on various multivariate statistical techniques for the analysis, visualization and interpretation of the resulting data. The suitability of the approach for visual interface design evaluation has been explored in four case studies involving overall 149 participants judging 51 websites. In each case study a different website domain was explored in order to examine whether the importance of certain design characteristics is context specific. Heterogeneity in preferences and perceptions was also studied showing that average construct scores are only representative for subsections of the participant sample. In order to aid the preference interpretation process additional data about study websites have been collected from three distinct sources:
a) Subjective construct ratings provided by the participants after preference evaluation
b) Descriptive attribute ratings obtained from trained expert panel on the same websites
c) Objective measures of visual characteristics of the websites
In each case study the potential of these types of measurements to explain preference variance has been investigated individually and in combination. The results showed that depending on the characteristics of each case study varying combinations of these types of data had the best explanatory power. A variety of methods (e.g. Internal and External PM) and statistical techniques (e.g. Principal Component Analysis (PCA), Generalized Procrustes Analysis (GPA) and Partial Least Squares (PLS)) have been used in order to summarize and visualize participant preference data of all case studies. In general, the method proposed in this thesis has several advantages over other visual design evaluation methods as for example use of standardized questionnaires. The method is flexible and can be used in various stages of design development but most importantly it allows for the identification of important visual design characteristics without ignoring the diversity that exist both among users and among website domains. These advantages have been demonstrated in the visual design evaluation studies presented in this thesis involving websites from four distinct domains. / Ο στόχος της παρούσας διατριβής είναι η πρόταση και ανάπτυξη μεθόδου αξιολόγησης διεπιφανειών χρήστη που θα λαμβάνει υπόψη τόσο τα αντικειμενικά χαρακτηριστικά σχεδιασμού, όσο και την υποκειμενική διάσταση που διέπει αξιολογήσεις με επίκεντρο τον χρήστη. Για την επίτευξη του στόχου αυτού αναπτύχθηκε μέθοδος αξιολόγησης, η οποία βασίζεται στην συγκριτική αξιολόγηση εναλλακτικών σχεδιασμών κατά την φάση συλλογής δεδομένων και στην χαρτογράφηση προτίμησης κατά την φάση ανάλυσης αποτελεσμάτων. Για την διερεύνηση της καταλληλότητας της προτεινόμενης μεθόδου αξιολόγησης, διεξήχθησαν τέσσερις μελέτες περίπτωσης κατά τις οποίες αξιολογήθηκαν συνολικά 51 ιστοσελίδες από 149 αξιολογητές. Κάθε μελέτη περίπτωσης διερευνούσε διαφορετική κατηγορία ιστοσελίδων και διαφορετικά σενάρια χρήσης της μεθόδου (π.χ. φάση προδιαγραφών, αξιολόγηση πρωτοτύπων κ.α.), έτσι ώστε να αξιολογηθεί η δυνατότητα της μεθόδου να εφαρμοστεί σε διαφορετικές συνθήκες. Σημαντικό πλεονέκτημα της προτεινόμενης μεθόδου είναι η δυνατότητα αναγνώρισης ετερογένειας απόψεων του δείγματος, η οποία σε άλλες μεθόδους αξιολόγησης θεωρείται θόρυβος στα δεδομένα και παραβλέπεται. Τα αποτελέσματα των αξιολογήσεων αναδεικνύουν σημαντική ετερογένεια αλλά και σχετική συμφωνία στις προτιμήσεις και αντιλήψεις των συμμετεχόντων. Με στόχο την ερμηνεία των αποτελεσμάτων από τα πειράματα αξιολόγησης διερευνήθηκαν τρεις πηγές δεδομένων πέρα από τις ταξινομήσεις προτίμησης από τους συμμετέχοντες σε όλες τις μελέτες περίπτωσης:
α) αξιολογήσεις βάσει υποκειμενικών χαρακτηριστικών από τους ίδιους τους συμμετέχοντες που ταξινόμησαν τις ιστοσελίδες με βάση την προτίμηση τους
β) αξιολογήσεις περιγραφικών και αντικειμενικών σχεδιαστικών χαρακτηριστικών από ομάδα εκπαιδευμένων εμπειρογνωμόνων
γ) Αντικειμενικές μετρήσεις σχεδιαστικών χαρακτηριστικών με αυτόματα και ημιαυτόματα εργαλεία αναγνώρισης εικόνας
Η δυνατότητα να ερμηνευτούν οι προτιμήσεις των χρηστών με την βοήθεια αυτών των πηγών δεδομένων, διερευνήθηκε ξεχωριστά αλλά και σε συνδυασμό σε κάθε μελέτη περίπτωσης. Στόχος ήταν να αποτιμηθεί η δυνατότητα συσχέτισης δεδομένων που διακατέχονται από διαφορετικά επίπεδα υποκειμενισμού με τις προτιμήσεις των συμμετεχόντων. Ιδανικά, θα αρκούσαν αντικειμενικές μετρήσεις και δεν θα επιβαρύνονταν οι χρήστες με επιπλέον βαθμολογήσεις των διεπιφανειών. Τα αποτελέσματα όμως έδειξαν ότι ένας συνδυασμός αντικειμενικών και υποκειμενικών χαρακτηριστικών ήταν ο βέλτιστος για την επιτυχή ερμηνεία των προτιμήσεων των χρηστών. Η μέθοδος αξιολόγησης που προτείνεται στα πλαίσια αυτής της διατριβής παρουσιάζει συγκριτικά πλεονεκτήματα σε σχέση με την χρήση τυποποιημένων ερωτηματολόγιων που είναι η επικρατέστερη μέθοδος στον χώρο της επικοινωνίας ανθρώπου υπολογιστή. Τα πλεονεκτήματα αυτά σχετίζονται κυρίως με την ευελιξία της μεθόδου και γίνονται εμφανή στις μελέτες αξιολόγησης που διεξήχθησαν με στόχο την εφαρμογή της μεθόδου για την αξιολόγηση ιστοσελίδων που ανήκουν σε τέσσερα διαφορετικά πεδία εφαρμογής.
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