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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Robust light transport simulation in participating media / Robust light transport simulation in participating media

Vévoda, Petr January 2015 (has links)
Light transport simulation is used in realistic image synthesis to create physically plausible images of virtual scenes. Important components of the scenes are participating media (e.g. air, water, skin etc.). Efficient computation of light transport in participating media robust to their large diversity is still an open problem. We implemented the UPBP algorithm recently developed by Křivánek et al. It addresses the problem by combining several complementary previous methods using multiple importance sampling, and excels at rendering scenes where the previous methods alone fail. The implementation is available online, we focused on its thorough description to facilitate and support further research in this field. Powered by TCPDF (www.tcpdf.org)
122

Development of a universal bidirectional galvanic isolated switch module for power converter applications

Mokhalodi, Kopano 06 1900 (has links)
M. Tech. (Engineering: Electrical, Department Electronic Engineering, Faculty of Engineering and Technology), Vaal University of Technology / The global trends towards energy efficiency have facilitated the need for technological advancements in the design and control of power electronic converters for energy processing. The proposed design is intended to make the practical implementation of converters easier. The development of a universal bidirectional galvanic isolated switch module will be used to drive any MOSFET or IGBT in any position in any topology whether the load is AC or DC. Semiconductor switches are required and are also integrated for fast switching times in power converter applications The structure of the power switch module consists of an opto-coupler which will provide an isolation barrier for maximum galvanic isolation between the control circuitry and power stage. It also consists of a high performance gate drive circuit for high speed switching applications with a floating supply. / Telkom South Africa Ltd, TFMC Pty Ltd, M-TEC, THRIP
123

Functional study of potential sHSPs in Arabidopsis and tomato under environmental stress. / Functional study of potential sHSPs in Arabidopsis and tomato under environmental stress.

Escobar, Mariela Raquel 26 March 2019 (has links)
Las proteínas pequeñas de choque térmico (sHSP) responden a una amplia variedad de estreses ambientales, estabilizando proteínas parcialmente desplegadas y evitando su agregación irreversible, en forma independiente de ATP. En plantas, las sHSPs son especialmente diversas siendo las sHSPs de organelas una característica única de las plantas. La estructura primaria de las sHSP incluye una secuencia N-terminal no conservada de longitud variable, un dominio α-cristalino conservado (ACD) y una secuencia C-terminal corta no conservada. El dominio ACD representa una característica conservada presente en todas las sHSPs, sin embargo, no todas las proteínas que contienen un dominio ACD son sHSP. Las sHSPs pertenecen a una gran superfamilia, siendo su importancia funcional y fisiológica en gran parte desconocida. El objetivo de este trabajo fue dilucidar el rol de sHSPs de localización mitocondrial (sHSPs-M) en Arabidopsis thaliana y Solanum lycopersicum en situaciones de estrés ambiental, y caracterizar probables promotores bidireccionales que regulan la expresión de genes codificantes de proteínas con dominio ACD con orientación cabeza a cabeza en el genoma de Arabidopsis. Este trabajo cubre aspectos desde la organización genómica y la función de sHSPs-M en Arabidopsis hasta el rol de las sHSPs-M en la respuesta al estrés por frío de frutos de tomate. Para ello, se generaron plantas mutantes de Arabidopsis y de tomate utilizando la tecnología de silenciamiento génico por micro ARNs artificiales. Las plantas mutantes fueron analizadas en su proteoma, metaboloma y lipidoma en distintas condiciones de estrés. A continuación, se presenta un resumen de los resultados obtenidos. En la primera parte de este trabajo, se realizó la caracterización funcional de genes con orientación cabeza a cabeza en el genoma de Arabidopsis, que codifican para proteínas con ACD y las regiones intergénicas correspondientes. Se lograron identificar y caracterizar cuatro distintos promotores bidireccionales, entre ellos el promotor del gen At5g51440 que codifica una sHSP de localización mitocondrial (sHSP23.5). Los resultados obtenidos sugieren que el promotor bidireccional contenido en el par At5g51430-At5g51440 es fuertemente inducido por altas temperaturas en una dirección, pero no así en la dirección opuesta. El promotor contenido en el par At1g06460-At1g06470 mostró una actividad alta en ambas direcciones, teniendo por ello, un alto potencial de aplicación en ingeniería genética. Los dos promotores restantes mostraron mayor actividad en una dirección y, por lo tanto, pueden ser considerados como promotores bidireccionales asimétricos. El estudio funcional de los promotores seleccionados reveló el potencial biotecnológico de los mismos ya que pueden ser inducidos específicamente en una determinada condición (como altas temperaturas) en una o en ambas direcciones cuando sea necesario. En la segunda parte, se presenta la caracterización funcional de sHSP mitocondriales en condiciones de estrés y durante el desarrollo de Arabidopsis. Se identificaron tres genes parálogos en el genoma de Arabidopsis (At5g51440, At4g25200, y At1g52560), y se diseñaron microARN artificiales específicos para la obtención de plantas mutantes por silenciamiento (amiR simple, doble y triple). Las plantas amiR simples y dobles (para sHSP23.5 y sHSP23.6) no mostraron un fenotipo evidentemente afectado, probablemente debido a la compensación o redundancia funcional de las sHSP mitocondriales. Por otro lado, las plantas triple mutante amiR23.5/23.6/26.5 muestran un fenotipo alterado en las etapas vegetativa y reproductiva. Estas plantas presentan hojas pequeñas, células epidérmicas con áreas reducidas, pero no reducción en el número de células epidérmicas por hoja. Además, exhiben hojas cloróticas, raíces cortas y menor producción de semillas en comparación con las plantas Col-0. Las plantas triple amiR son considerablemente pequeñas debido a una alteración en el proceso de expansión celular, pero no en la proliferación celular, lo que indica una profunda alteración en el programa de desarrollo de la planta. En el análisis proteómico de las mutantes amiR se observó un aumento significativo de proteínas implicadas en el metabolismo, y alteración en la abundancia de varias proteínas relacionadas con la traducción, y con el funcionamiento y la estructura de los ribosomas. La triple mutante exhibió un mayor número de proteínas con abundancia alterada involucradas en estos procesos en comparación con las mutantes simples y doble amiR23.5/23.6. Estos cambios tan amplios observados en proteínas relacionadas con el funcionamiento de los ribosomas sugieren una posible alteración en la función normal de los mismos. Los resultados presentados en este trabajo proporcionan evidencias sobre el importante rol de las sHSPs-M no sólo en la respuesta a las altas temperaturas, sino también durante el desarrollo de la planta de Arabidopsis. Los resultados indican que una compensación funcional podría ser responsable del fenotipo observado en las plantas mutantes con niveles reducidos de cada sHSPs-M individual. Sin embargo, la reducción simultanea de las tres sHSPs-M causó una profunda alteración en la función normal de mitocondrias y ribosomas, afectando gravemente el metabolismo energético y la homeostasis celular, lo que llevó a alteraciones en el desarrollo correcto de la planta. En la última parte de este trabajo, las consecuencias de la disminución de la proteína sHSP23.8 de localización mitocondrial en frutos de tomate fueron investigadas. Los frutos fueron analizados en su fenotipo y en la susceptibilidad al daño por frío. Los frutos de las plantas mutantes amiR23.8 que fueron conservados en frío mostraron mayor pérdida de agua y de electrolitos en el tejido pericárpico en comparación con frutos WT. El deterioro observado en los frutos amiR23.8 indica que estos frutos mutantes son mayormente susceptibles al estrés por frío desarrollando síntomas de daño por frío. El lipidoma de los frutos amiR23.8 frigoconservados mostró cantidades alteradas de glicerolípidos, y los niveles de lípidos saturados en amiR23.8 disminuyeron luego del tratamiento con frío, pero no por debajo de los niveles encontrados en frutos WT en condiciones normales. Lo opuesto se encontró en el porcentaje relativo de lípidos insaturados, con niveles significativamente más bajos de insaturaciones en frutos amiR23.8 en condiciones normales y después del enfriamiento. Los resultados presentados indican una degradación diferencial de lípidos extraplastídicos y plastídicos en frutos amiR23.8, y alteraciones en la remodelación del lipidoma luego del estrés por frío, lo que podría conducir a una mayor sensibilidad al daño por frío. Los resultados discutidos aquí indican que la proteína sHSP23.8 podría estar directamente involucrada en los mecanismos de protección contra el estrés por frío en frutos de tomate.
124

Dinâmicas emergentes na família de memórias associativas bidirecionais caóticas e sua habilidade para saltar passos / Emergent dynamics in family of chaotic bidirectional associative memories and its ability to skip steps

Bueno, Luciana Pavani de Paula 19 May 2006 (has links)
Nesta tese, uma família de memórias associativas bidirecionais caóticas (família C-BAM) é proposta, implementada e testada com o objetivo de estender a relevância da presença e do estudo do fenômeno caótico a modelos de redes associativas. Na modelagem da família C-BAM, todos os neurônios da memória associativa bidirecional caótica (BAM), BAM com atraso e BAM exponencial (eBAM) foram substituídos por neurônios caóticos. Cada parâmetro do neurônio caótico na família C-BAM tem sua influência estimada através do planejamento de experimentos, em diferentes dinâmicas. Com base no planejamento de experimentos, valores de parâmetros são selecionados a fim de ilustrar a emergência de comportamentos dinâmicos como bifurcação, caos determinístico e crise. A existência de dinâmicas caóticas é confirmada pelo cálculo dos expoentes de Lyapunov. Experimentos empíricos mostraram que a dinâmica caótica modifica a acessibilidade à memória da família C-BAM. Ao invés de recuperar um único par, como a família BAM fazia, a versão caótica é capaz de gerar uma grande diversidade de padrões recuperados, envolvendo complexas transições entre os padrões armazenados, para algumas variações paramétricas. Tal comportamento permite à família C-BAM acessar padrões inacessíveis às redes BAMs originais. Além disso, a nova acessibilidade à memória, na qual seqüências de recuperação (com diferentes tamanhos) compostas de padrões treinados e não treinados têm emergido, pode ser usada para modelar a habilidade de um indivíduo saltar passos na solução de uma tarefa. Esta tese seleciona a rede C-BAM para ilustrar que a seqüência de recuperação da rede pode modelar a habilidade de um noviço ou a habilidade de um especialista executar uma tarefa. Embora a família C-BAM possa alcançar todos os padrões armazenados durante o comportamento caótico, ela não consegue convergir para um padrão específico. Duas estratégias de controle são propostas para permitir que as redes caóticas convirjam para a memória desejada: o método de controle por pinagem e um método de controle adaptativo. Conseqüentemente, os modelos C-BAM podem, de fato, realizar a hetero-associação de memórias antes inacessíveis, e a rede C-BAM pode estabilizar-se no estado final de uma tarefa, dado o primeiro estado / In this thesis, a family of bidirectional associative memories (C-BAM family) is proposed, implemented and tested to extend the study of chaotic phenomenon in associative models. In the C-BAM model, all the original neurons of bidirectional associative memory (BAM), BAM with delay and exponenetial BAM (eBAM) were substituted for chaotic neurons. Based on the experimental design, values of C-BAM family parameters are set to illustrate the emergence of a diversity of dynamic behavior, such as bifurcation, deterministic chaos and crisis. The existence of the chaotic dynamics is confirmed by calculation of Lyapunov exponents. Empiric experiments showed that the chaotic dynamics modifies the behavior of memory accessibility. Instead of recalling a single pair, as BAM did, its chaotic version yielded a wide diversity of recalled patterns, involving complex transitions via memorized patterns for some parametric variations. Hence, C-BAM family can access patterns that original BAM family cannot. Moreover, the new way of memory accessibility, in which several recall sequences (with distinct sizes) composed of trained and nontrained patterns have emerged, can be used to model the ability of skipping steps by an individual in a task solution. This thesis selected C-BAM network to illustrate that the retrieval sequence can model the ability of a novice or the ability of an expert to execute a task. There are also illustrated cases in which a novice recall can be transformed into an expert recall through parametric variation. Although C-BAM family can reach all stored patterns during the chaotic behavior, it can not converge towards a specific pattern, consequently a desired output is not produced. In this thesis, two control strategies are proposed in order to make the chaotic networks to converge towards the desired memory: the pinning control method and the adaptive control method. Consequently, the C-BAM models can effectively realize the correct heteroassociation to former non-accessible memories and the C-BAM network can quickly be stabilized in the final state of a task, given the first state
125

Bidirectional transport by molecular motors

Müller, Melanie J. I. January 2008 (has links)
In biological cells, the long-range intracellular traffic is powered by molecular motors which transport various cargos along microtubule filaments. The microtubules possess an intrinsic direction, having a 'plus' and a 'minus' end. Some molecular motors such as cytoplasmic dynein walk to the minus end, while others such as conventional kinesin walk to the plus end. Cells typically have an isopolar microtubule network. This is most pronounced in neuronal axons or fungal hyphae. In these long and thin tubular protrusions, the microtubules are arranged parallel to the tube axis with the minus ends pointing to the cell body and the plus ends pointing to the tip. In such a tubular compartment, transport by only one motor type leads to 'motor traffic jams'. Kinesin-driven cargos accumulate at the tip, while dynein-driven cargos accumulate near the cell body. We identify the relevant length scales and characterize the jamming behaviour in these tube geometries by using both Monte Carlo simulations and analytical calculations. A possible solution to this jamming problem is to transport cargos with a team of plus and a team of minus motors simultaneously, so that they can travel bidirectionally, as observed in cells. The presumably simplest mechanism for such bidirectional transport is provided by a 'tug-of-war' between the two motor teams which is governed by mechanical motor interactions only. We develop a stochastic tug-of-war model and study it with numerical and analytical calculations. We find a surprisingly complex cooperative motility behaviour. We compare our results to the available experimental data, which we reproduce qualitatively and quantitatively. / In biologischen Zellen transportieren molekulare Motoren verschiedenste Frachtteilchen entlang von Mikrotubuli-Filamenten. Die Mikrotubuli-Filamente besitzen eine intrinsische Richtung: sie haben ein "Plus-" und ein "Minus-"Ende. Einige molekulare Motoren wie Dynein laufen zum Minus-Ende, während andere wie Kinesin zum Plus-Ende laufen. Zellen haben typischerweise ein isopolares Mikrotubuli-Netzwerk. Dies ist besonders ausgeprägt in neuronalen Axonen oder Pilz-Hyphen. In diesen langen röhrenförmigen Ausstülpungen liegen die Mikrotubuli parallel zur Achse mit dem Minus-Ende zum Zellkörper und dem Plus-Ende zur Zellspitze gerichtet. In einer solchen Röhre führt Transport durch nur einen Motor-Typ zu "Motor-Staus". Kinesin-getriebene Frachten akkumulieren an der Spitze, während Dynein-getriebene Frachten am Zellkörper akkumulieren. Wir identifizieren die relevanten Längenskalen und charakterisieren das Stauverhalten in diesen Röhrengeometrien mit Hilfe von Monte-Carlo-Simulationen und analytischen Rechnungen. Eine mögliche Lösung für das Stauproblem ist der Transport mit einem Team von Plus- und einem Team von Minus-Motoren gleichzeitig, so dass die Fracht sich in beide Richtungen bewegen kann. Dies wird in Zellen tatsächlich beobachtet. Der einfachste Mechanismus für solchen bidirektionalen Transport ist ein "Tauziehen" zwischen den beiden Motor-Teams, das nur mit mechanischer Interaktion funktioniert. Wir entwickeln ein stochastisches Tauzieh-Modell, das wir mit numerischen und analytischen Rechnungen untersuchen. Es ergibt sich ein erstaunlich komplexes Motilitätsverhalten. Wir vergleichen unsere Resultate mit den vorhandenen experimentellen Daten, die wir qualitativ und quantitativ reproduzieren.
126

Implementation of a Dual-Active-Bridge Bidirectional Isolated DC to DC Converter in Home Area Network

Lo, Sheng-Chieh 13 September 2012 (has links)
In recent years, smart gird has received much attention, and many researchers have devoted to home area network (HAN) to improve the efficiency of grid. This thesis proposes a bidirectional isolated DC-DC converter (Dual Active Bridge, DAB) with phase shift control to implement the concept of HAN. Li+Fe battery is used as storage device of the converter, and a bidirectional communication between Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW) and Digital Signal Processor (DSP) is realized by CAN-bus. By setting the current command given by LabVIEW system, the converter is able to charge the Li+Fe battery with constant current and constant voltage method as well as discharge the Li+Fe battery with constant current. Operation principle of the converter and the associated loss are presented.
127

High-power bi-directional DC/DC converters with controlled device stresses

Han, Sangtaek 11 May 2012 (has links)
The objective of the research is to develop a cost-effective high-power bi-directional dc/dc converter with low total-device ratings, reduced system parasitic effects, and a wide input/output range. Additional objectives of the research are to develop a small-signal model and control methods, and to present performance characterizations. Device stresses in the proposed topology are controlled to maintain minimal levels by varying the duty ratio and phase-shift angle between the primary and the secondary bridges, which results in a low total-device rating, when compared to conventional bi-directional dc/dc topologies. In the proposed topology, soft switching, which reduces power loss, can be realized under specific operating conditions. When the condition that causes minimal device stress is satisfied, zero-voltage switching (ZVS) can be obtained. In the research, ZVS capability is explored for a wide range of voltage conditions as well as for the minimal device-stress condition. The performance characterization includes verifying the soft-switching regions and power-loss estimation. Another part of the thesis is the controller design of the converter. Small-signal models and feedback controllers are developed, and the controllers are experimentally validated. Because in the isolated high-frequency converters, transformer saturation is an important issue, a method to prevent transformer saturation is proposed and experimentally validated.
128

Relations prédictives entre traits de personnalité, attitudes parentales et comportements perturbateurs : un modèle transactionnel de l'enfance à l'adolescence

Carignan, Véronique 08 1900 (has links)
Plusieurs études ont confirmé que certains traits de personnalité des enfants et certaines attitudes et pratiques éducatives de leurs parents constituaient des prédicteurs des comportements perturbateurs à l’adolescence. Toutefois, la majorité des recherches ont adopté un modèle postulant des relations directes et indépendantes entre ces facteurs de risque et des comportements perturbateurs. Le modèle transactionnel est plus réaliste parce qu’il postule des relations bidirectionnelles à travers le temps entre ces deux facteurs de risque. Cette étude visait à vérifier l’existence de relations bidirectionnelles entre les traits de personnalité des enfants et les attitudes parentales de leur mère mesurés à deux reprises durant l’enfance (à 6 et 7 ans), pour ensuite vérifier si les comportements perturbateurs des enfants mesurés à l’adolescence (15 ans) pouvaient être prédits par les traits de personnalité et les attitudes parentales. Les données utilisées proviennent d’une étude longitudinale prospective de 1000 garçons et 1000 filles évalués à plusieurs reprises de la maternelle à l’adolescence. Six traits de personnalité des enfants et deux attitudes parentales ont été évalués par les mères à 6 et 7 ans, alors que les diagnostics de troubles perturbateurs (trouble des conduites, trouble oppositionnel avec provocation, trouble de déficit de l’attention/hyperactivité) ont été évalués par les adolescents et les mères à 15 ans. Afin de tester les hypothèses de recherche, des analyses de cheminement (« path analysis ») multi-groupes basées sur la modélisation par équations structurales ont été utilisées. Les résultats ont confirmé la présence de relations bidirectionnelles entre les traits de personnalité de l’enfant et les attitudes parentales durant l’enfance. Toutefois, peu de relations étaient significatives et celles qui l’étaient étaient de faible magnitude. Les modèles multi-groupes ont par ailleurs confirmé la présence de relations bidirectionnelles différentes selon le sexe. En ce qui concerne la prédiction des comportements perturbateurs, de façon générale, surtout les traits de personnalité et les attitudes parentales à 6 ans (plutôt qu’à 7 ans) ont permis de les prédire. Néanmoins, peu de relations prédictives se sont avérées significatives. En somme, cette étude est une des rares à avoir démontré la présence de relations bidirectionnelles entre la personnalité de l’enfant et les attitudes parentales avec des données longitudinales. Ces résultats pourraient avoir des implications théoriques pour les modèles explicatifs des comportements perturbateurs, de même que des implications pratiques pour le dépistage des enfants à risque. / Several studies confirmed that some children’s personality traits and parental attitudes constitute risk factors of later disruptive behaviors during adolescence. However, most research has adopted a model postulating direct and independent relations between these risk factors and disruptive behaviors. The transactional model is more realistic because it postulates bidirectional relations over time between these two risk factors. Even though the transactional model is popular amongst researchers, there is in fact very little research formally demonstrating the existence of bidirectional relations with longitudinal data during childhood. This study aimed at verifying the existence of bidirectional relations between children’s personality traits and their mothers’ parental attitudes measured on two occasions during childhood (ages 6 and 7), and later verifying if individuals’ disruptive behaviors during adolescence (age 15) could be predicted by children’s personality traits and parental attitudes. The data came from a prospective longitudinal study of 1000 boys and 1000 girls assessed on various occasions from kindergarten through adolescence. Six children’s personality traits and two parental attitudes were assessed by mothers at ages 6 and 7, while the disruptive behavior diagnostics (conduct disorder, oppositional defiant disorder, attention deficit hyperactivity disorder) were assessed by adolescents ant their mothers at age 15. In order to test the research hypotheses, multiple-group path analyses based on structural equations modeling were used. The results confirmed the presence of bidirectional relations between children’s personality traits and parental attitudes during childhood. Nevertheless, there were few significant relations and most of them were of small size. Multiple-group models also confirmed the presence of gender-specific bidirectional relations. With regards to the prediction of disruptive behaviors, especially children’s personality traits and parental attitudes at age 6 (rather than age 7) were predictive. Nonetheless, few predictive relations turned out to be significant. Overall, this study is one of the rare to demonstrate the presence of bidirectional relations between children’s personality and parental attitudes with longitudinal data. These results could have theoretical implications for explanatory models of disruptive behaviors, as well as practical implications for early screening of children at risk.
129

Forest attributes from multi-angle multi-date remotely sensed data

Dyk, Andrew 30 August 2010 (has links)
Multi-Angle, Multi-Date, Hyperspectral imagery of forests have been used to provide accurate estimates of the canopy characteristics. This thesis investigated the influence of various forest attributes on the spectral reflectance over time and view direction. The Compact High Resolution Imaging Spectrometer (CHRIS) is aboard the ESA PROBA satellite. The revisits of the CHRIS multi-angle images have been used to improve the accuracies of forest species recognition and stand densities compared to a nadir view only. Multi-angle data for CHRIS analysis of forest species produced higher accuracy and were easier to obtain than multi-date date. 5-Scale, a radiative transfer model, and CHRIS data have been compared as inputs into Partial Least Squares (PLS), a fullspectrum analytical method that offers relations between forest stand parameters and the resulting spectra. The resulting coefficients highlight where (view angle and spectral regions) within the multi-angle spectra contributed to estimating the various forest parameters. Methodology of collecting spectral calibration data in the field and the unique pre-processing challenges have been described.
130

初診斷乳癌患者的因應策略與心理症狀之關係研究 / The relationships of coping strategies and psychological symptoms on newly-diagnosed breast cancer patient

鄭麗芬, Te, Lay Fuen Unknown Date (has links)
本研究旨在比較不同背景和臨床因素的乳癌患者其因應策略、正向情緒和心理症狀的差異情形。本研究除了關注個體所採取的因應策略與情緒的關聯性;另一方面,研究者認為患者的情緒亦可能影響其因應策略之選擇,因此因應策略與情緒間的變化關係,亦為本研究目的之一。 本研究採立意取樣,並以中部某一教學醫學乳房中心初診斷之乳癌患者共計113位為研究對象,蒐集患者之「基本資料表」、「短版因應策略量表」、「醫院版焦慮-憂鬱量表」和「情緒平衡量尺」,並以術後3個月和6個月進行追蹤研究。 資料處理以相關分析、t考驗、單因子變異數分析及階層迴歸分析等統計方法為主。由於本研究擬以Brief COPE作為臺灣乳癌病患因應壓力之測量工具,因此將採用探索性因素分析(Exploratory Factor Analysis;EFA),探討此量表在初診斷乳癌患者身上的因素結構。 依據本研究問題與假設,主要發現摘述如下: 一、本研究以主成分分析法抽取Brief COPE量表因素,並以斜交轉軸進行因素轉軸,依據陡坡圖和平行分析結果抽取三個因素。此三因素的解釋總變異量為62.1%。研究者將因素I命名為「趨近因應」;因素II命名為「情緒性因應」和因素III命名為「逃避因應」。 二、教育程度、收入和有無職業與正向情緒呈正相關;現有小孩人數和年齡與正向情緒呈負相關;年齡和副作用與憂鬱具有正向關係,教育程度則與憂鬱呈負相關;副作用與焦慮呈正相關。有無結婚、有無職業、教育程度、收入、乳房重建與趨近因應呈正相關,期數和年齡則和趨近因應有顯著負相關;有無職業和情緒性因應呈正相關。 三、乳癌患者於術後3、6個月最常採用的因應策略為趨近因應,其次為情緒性因應,最少採用逃避因應。 四、焦慮對逃避和趨近因應有獨特的預測力,即焦慮程度愈高會愈使用逃避和趨近因應策略;憂鬱則對趨近因應有獨特的預測力,憂鬱程度愈高者,其趨近因應的使用愈少;在因應策略的部分,只有趨近因應可顯著預測正向情緒;正向情緒在趨近因應和焦慮的關係中並無法形成部份或完全中介之角色。 最後,根據研究結果與限制提出若干具體建議,以供臨床工作者及未來研究之相關人員參考。 / The purpose of this study is to explore the differences of coping strategies, positive affect and psychological symptoms among newly-diagnosed breast cancer patients in different sociodemographic backgrounds. Research has found that coping strategies predict psychological outcomes; however, a few studies have also reported that psychological symptoms could predict the use of coping strategies. Therefore, the relationship between coping strategies and psychological symptoms was the first aim of the current study. One-hundred and thirteen participants were recruited by purposive sampling. The data were draw from newly-diagnosed breast cancer patients in a breast center unit at a hospital in central of Taiwan. Demographic and clinical data were gathered at the first time point, and the Brief Coping Orientations to Problems Experienced scale (Brief COPE), the Hospital Anxiety and Depression Scale (HADS), Positive Affect subscale of Affect Balance, and side effect checklists were gathered 2 times during the first 3- and 6-month after discharge respectively. Pearson product-moment correlation, t-test, one-way ANOVA, post Scheffe test and hierarchical regression analysis were applied. In an attempt to confirm the factor structure of the Brief COPE, the Exploratory Factor Analyses (EFA) were performed before those analyses. The major findings of the current study were as follows: 1.Using principal components factor analysis with oblique rotation, scree plot and parallel analyses revealed three factors for the Brief COPE were the best factor structure of the current sample: (1) approach coping, (2) emotional coping, and (3) avoidance coping. These 3 factors accounted for 62.1% of the total variance of the data. 2.Education, income and employment status were significantly correlated with positive affect. Number of kids and age were found to be inversely correlated with positive affect. Age and side effects were positively correlated with depression. Side effects were found to be correlated with anxiety. Marital status, employment status, cancer stage, education, income, age, breast reconstruction surgery were found to be correlated with approach coping. Meanwhile stage and age were found to be negatively correlated with emotional coping. 3.Approach coping was the most commonly used coping strategies, while avoidance coping was the least commonly used coping strategies. 4.Anxiety could reliably predict the use of avoidance and approach coping. High anxiety level predicted more use of avoidance and approach coping, whereas depression predicted the use of approach coping, high depressive mood predicted less use of approach coping. Approach coping predicted higher positive affect, but positive affect was fail to be the mediator between approach coping and anxiety. Implications for these results were discussed. The results can also serve as a helpful reference for healthcare professionals.

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