Organisational commitment, viewed as a measurable psychological state, is a core variable of interest in Organisational Behaviour research. It has been studied for more than four decades, largely focusing on the identification of its antecedents and consequences. One widely used conceptualisation is Meyer and Allen‘s (1991) three-component model of commitment, which considers commitment as having three forms: affective, continuance and normative (emotional attachment to an organisation, the perceived cost associated with leaving it and the perceived obligation to remain in it). This research contributes in three ways to improving our understanding of public-sector work behaviour, with particular reference to organisational commitment. Firstly, it examines the multi-dimensionality of organisational commitment. Secondly, it explores the relationships between Meyer and Allen‘s three components, modifying the concept of continuance commitment to include two sub-components, high personal sacrifice and low perceived alternatives, thus proposing a four-factor model, Antecedents and Consequences of Organisational Commitment Components (ACOCC). Thirdly, it considers antecedent variables, including Hofstede‘s (1980) four cultural dimensions (individualism/collectivism, uncertainty avoidance, power distance and masculinity/femininity), as well as selected consequences: in role behaviour, organisational citizen behaviour and employee intention to leave. These selected variables are deemed to be suitable for Saudi Arabian culture and have never been tested before in that context. The study investigates how the commitment components are associated with and mediate relationships with the set of possible work behaviours. Using a sample of 700 employees from different organisation levels (drawn from 16 Saudi ministries in two cities, Riyadh and Jeddah) the hypotheses were tested through structural equation modelling, which confirmed the fit of the proposed recursive ACOCC model. The regression paths were significant between the antecedents (opportunities for learning, impersonal bureaucratic arrangements and Hofstede‘s four cultural dimensions) and affective and normative commitment, as well as for continuance commitment for reasons of high personal sacrifice. Intention to leave and organisational citizen behaviour were fully mediated by the commitment components. Thus the findings reveal the level and form of organisational commitment among public-sector employees and of relationships between the antecedents and consequences of that commitment in a non-Western culture, specifically Saudi Arabia. In particular, they highlight the significant mediation role of organisational commitment. The findings also permit exploration of a number of issues pertaining to cultural dimensions impacting on organisational commitment. Noteworthy here, for example, is the high degree of uncertainty avoidance found among Saudi public-sector top-level managers. These different results have important implications for the nature and management of commitment among government employees in Saudi Arabia and the Gulf Cooperation Council countries as a whole.

Organizational commitment (OC) is a psychological state that binds an employee to an organization, and the Three-Component Model of organizational commitment (Meyer and Allen, 1991) posits that employees bind with their organizations as a result of desire (affective commitment), need (continuance commitment) and obligation (normative commitment). Similarly, relationship commitment between two people also has been conceived as a psychological state (Rusbult and Buunk, 1993), and Arriaga and Agnew (2001) outlined affective, cognitive and conative components of the state. This exploratory study examined the similarities between these conceptually parallel commitment models by determining how the dimensions of the two types of commitment correlate with one another, attachment style (Bowlby 1969/1982) and locus of control (Rotter, 1966). Data collected from 171 working adults yield several noteworthy associations and suggest future directions of inquiry.

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京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23536号 / エネ博第427号 / 新制||エネ||81(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 石原 慶一, 教授 佐川 尚, 准教授 奥村 英之 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Recent studies indicate that employees distinguish between commitments to interpersonal foci within the organization, such as supervisors and coworkers. Often, these commitments account for variance in outcomes incremental to organizational commitment (e.g., Becker, 1992). Unfortunately, research has tended to focus on affective forms of commitment to foci, while ignoring normative and continuance commitment. To address this gap, the current study proposed and tested models of commitment to foci which incorporate normative and continuance commitment in addition to affective commitment. Results showed some parallels with findings concerning organizational commitment. Much like organizational commitment, support from a focus relates to affective commitment to that focus, while expectations from a focus predict normative commitment to the focus. Additionally, both affective and normative commitment to supervisors and coworkers predicted favorable outcomes, but continuance commitment did not. In line with researchers recommendations (e.g., Johnson, Groff & Taing, in press), interactions among different bases and foci of commitment were also examined. Exploratory analyses suggested a three-way interaction between affective organizational, supervisor, and coworker commitment for predicting in-role performance.

abstract: Microfluidics is the study of fluid flow at very small scales (micro -- one millionth of a meter) and is prevalent in many areas of science and engineering. Typical applications include lab-on-a-chip devices, microfluidic fuel cells, and DNA separation technologies. Many of these microfluidic devices rely on micron-resolution velocimetry measurements to improve microchannel design and characterize existing devices. Methods such as micro particle imaging velocimetry (microPIV) and micro particle tracking velocimetry (microPTV) are mature and established methods for characterization of steady 2D flow fields. Increasingly complex microdevices require techniques that measure unsteady and/or three dimensional velocity fields. This dissertation presents a method for three-dimensional velocimetry of unsteady microflows based on spinning disk confocal microscopy and depth scanning of a microvolume. High-speed 2D unsteady velocity fields are resolved by acquiring images of particle motion using a high-speed CMOS camera and confocal microscope. The confocal microscope spatially filters out of focus light using a rotating disk of pinholes placed in the imaging path, improving the ability of the system to resolve unsteady microPIV measurements by improving the image and correlation signal to noise ratio. For 3D3C measurements, a piezo-actuated objective positioner quickly scans the depth of the microvolume and collects 2D image slices, which are stacked into 3D images. Super resolution microPIV interrogates these 3D images using microPIV as a predictor field for tracking individual particles with microPTV. The 3D3C diagnostic is demonstrated by measuring a pressure driven flow in a three-dimensional expanding microchannel. The experimental velocimetry data acquired at 30 Hz with instantaneous spatial resolution of 4.5 by 4.5 by 4.5 microns agrees well with a computational model of the flow field. The technique allows for isosurface visualization of time resolved 3D3C particle motion and high spatial resolution velocity measurements without requiring a calibration step or reconstruction algorithms. Several applications are investigated, including 3D quantitative fluorescence imaging of isotachophoresis plugs advecting through a microchannel and the dynamics of reaction induced colloidal crystal deposition. / Dissertation/Thesis / Ph.D. Mechanical Engineering 2011

The Three-Component Model of organizational commitment (TCM) by Meyer and Allen (1991, 1997) is widely regarded as the most dominant model in organizational commitment research (Cohen, 2003, 2007). However, recent research by Solinger et al. (2008) questioned the legitimacy of the TCM as a general model of organizational commitment. More specifically, the authors criticized the TCM for grouping affective commitment as an attitude toward target with continuance and normative commitment as attitudes toward behaviors under one general label of attitudinal construct. Based on the Theory of Reasoned Action (TRA; Ajzen & Fishbein, 1980), Solinger et al. (2008) argued that we should consider organizational commitment strictly as an attitude toward the organization (i.e., affective commitment). Based on Eagly and Chaiken's (1993) composite attitude-behavior model, the current study tested the reconceptualization of organizational commitment as a unidimensional construct reflecting employees' attitudes toward the organization (i.e., affective commitment) in predicting several organizational behaviors (i.e., considerate voice, production deviance, and behavioral engagement). In addition, I also investigated whether these organizational behaviors could be better explained by adding different classes of behavioral expectancies (i.e., utilitarian, normative and self-identity expectancies) as antecedents. Finally, I tested the mediating roles of attitude toward behaviors in the relationship between affective commitment and three behavioral expectancies and the three organizational behaviors. A sample of 258 employees in a large-sized organization in China was obtained for this study. The results suggested that none of the hypotheses of the current study was supported by the evidence in the current study. In particular, affective commitment and three classes of behavioral expectancies did not significantly predict their corresponding behaviors. In addition, I also did not find the evidence for the indirect effects from affective commitment and the behavioral expectancies on the behaviors. Several alternative explanations were provided for the results. Among those, the lack of compatibility between affective commitment and the behaviors, the existence of moderators (e.g. national culture), the lack of necessary control to perform the behaviors successfully are key factors that might lead to the current findings. Although none of the hypotheses was supported, I found limited empirical supports for the reconceptualization of organizational commitment strictly as the attitude toward the organization and that organizational behaviors could be better explained by adding appropriate behavioral expectancies to the model (Solinger et al., 2008). Finally, theoretical and practical implications of the current study as well as directions for future research are discussed.

Le sujet de thèse sur lequel je travaille depuis trois ans est l’étude et le développement des systèmes photoamorceurs pour des applications holographiques. Ce travail a lieu en collaboration avec l’équipe BMS (Bayer Material Science) de Bayer-Leverkusen (Allemagne). Mes études se sont limitées aux systèmes utilisables avec une source d’irradiation appartenant à la partie visible du spectre électromagnétique de la lumière (400 nm – 700 nm).Parmi les différents types des réactions de polymérisation, nous avons choisi la polymérisation radicalaire. L’étape cruciale dans cette réaction réside dans la génération des radicaux qui amorcent la réaction. Ces derniers sont formés par transformation, via absorption de lumière, d’un composé photosensible. La formation de ces espèces est en général en compétition avec plusieurs processus de désactivation. Les polymérisations radicalaires sont en particulier fortement inhibées par l’oxygène de l’air. Pour réduire l’effet de l’oxygène et pour avoir des conditions comparables à ceux appliqués dans l’industrie, nos échantillons ont été préparés en utilisant la technique laminée (l’échantillon est mis entre deux films de polypropylène). [...] / The subject of the thesis I have been working on for three years is the study and development of photoinitiating systems for holographic applications. This work takes place in collaboration with the BMS (Bayer Material Science) team from Bayer Leverkusen (Germany). My studies have been limited to systems used with a radiation source belonging to the visible part of the electromagnetic spectrum of light (400 nm - 700 nm). Among the different types of polymerization reactions, we chose the radical polymerization. The critical step in this reaction is the generation of radicals which initiate the reaction. These are formed by transformation via absorption of light of a photosensitive compound. The formation of these species is generally in competition with several deactivation process. [...]

[pt] O estudo do escoamento intermitente de gás e líquido é de enorme relevância. Devido a sua vasta ocorrência em diversos problemas industriais, como na indústria do petróleo, em escoamentos de água e vapor em trocadores de calor e em sistemas de refrigeração de usinas nucleares, diversos estudos experimentais e numéricos buscam obter um conhecimento mais profundo deste complexo fenômeno. Devido a esta complexidade, se fazem necessários experimentos detalhados de maneira a dar suporte aos modelos matemáticos desenvolvidos. O presente trabalho descreve um estudo experimental de um escoamento turbulento gás-líquido no regime intermitente para tubo horizontal. As técnicas de velocimetria por imagem de partícula estereoscópica de alta frequência (SPIV ) e fluorescência induzida por laser (LIF) foram usadas para medir todos os três componentes do vetor de velocidade em diferentes seções do tubo, referenciadas pelo nariz da bolha de gás. A seção de testes consistiu de uma tubulação de acrílico com diâmetro interno de 40mm e 17,7m de comprimento. Os fluidos de trabalho utilizados foram água e ar, com velocidades superficiais de jL igual 0,3 0,4 e 0,5m/s e jG igual 0,5m/s que formaram o padrão de escoamento intermitente. Um sistema de sensores fotossensíveis foi utilizado para medir a velocidade de translação da bolha de gás, além de acionar o sistema SPIV. Desta forma, foi possível determinar os campos médios das três componentes de velocidade da fase líquida do escoamento turbulento gás-líquido em regiões de interesse na vizinhança da bolha alongada. Os dados obtidos revelaram a influência das bolhas de gás de maior velocidade, na dinâmica do campo de velocidade do líquido. Tais dados contém informações valiosas que contribuem não apenas para uma melhor compreensão da física que rege o escoamento, mas também como forma de validação e aprimoramento de modelos numéricos. / [en] The analysis of gas-liquid intermittent flow in horizontal pipes is of great relevance importance due its applications in many industrial problems, such as in the petroleum industry, boiler and heat exchanger tubes and cooling systems of nuclear power plants. A considerable number of experimental and analytical studies have been carried out on the pursuit of a deeper knowledge of this complex phenomenon. The present work describes an experimental study of a horizontal, gas-liquid pipe flow in the intermittent regime. Experimental techniques such as high frequency stereoscopic particle image velocimetry (SPIV ) and laser induced fluorescence (LIF), were applied in order to obtain all three components of the velocity vector at different pipe sections, referred to the gas bubble nose tip. A 40mm inner diameter, 17.7m long acrylic pipe was used as test section (L/D approximately 450). The working fluids, water and air formed the intermittent flow pattern, with superficial velocities of jL equal 0.3, 0.4 and 0.5 m/s and jG equal 0.5 m/s. A set of three photogate sensors, equally-spaced along the pipe, were used to measure the bubble translational velocities, and to trigger the SPIV system, allowing for the determination of ensemble-averaged, threecomponent velocity fields of the turbulent liquid flow in cross-stream planes around the gas bubble. The original data obtained revealed the influence of the faster-moving gas bubbles on the dynamics of the liquid velocity field, providing valuable information that contribute to a better understanding of the physics governing the flow, also serving for the validation of numerical simulations.

為了處理在願付價格的研究中，極端受訪者對於估計結果所造成的誤差。本文沿用Tsai(2005)所建議採用的三要素混合模型，將受訪者區分為價格再高都願意支付、願意支付合理價格以及價格再低都不願意支付等三種類型。在評估願付價格時，以加速失敗模型(accelerated failure time model，簡稱AFT model)針對願意支付合理價格的受訪者進行估計，並且在考慮不同起價點可能會造成不同程度的起價點偏誤(starting point bias)或是定錨效果(anchoring effect)的情形下，提出一個起價點偏誤調整模型來做探討。我們並以CVDFACTS中的高血壓之願付價格資料進行實證分析。分析結果發現，教育程度越高的男性對於能降低高血壓病患罹患心臟血管相關疾病之新藥願意付較高的金額。此外我們也發現在此筆資料中，不同起價點確實會造成不同程度的偏誤，經由偏誤調整後會得到較高的願付金額。 / A study of willingness-to-pay often suffers from the bias introduced by extreme respondents who are willing to or not willing to pay any price. To overcome the problem, a three-component model proposed by Tsai (2005) is adopted. Under such a circumstance, respondents are classified into three categories, i.e. respondents who are willing to pay any price, unwilling to pay any price, or willing to pay a reasonable price. The willingness-to-pay for those subjects who are willing to pay a reasonable price is again modeled by an accelerated failure time model (AFT model). In this study, we, however, propose an unified model that allows us to look into the issue related to starting point bias and anchoring effect, simultaneously. Willingness-to-pay for cardiovascular disease treatment from a longitudinal follow-up survey- CVDFACTS, is investigated using the new model. Through the use of the model, we are able to detect the effects of starting point biases, and make a proper adjustment accordingly. Our analysis indicates that male respondents with higher education level have an inclination to pay higher price for the new treatment. Besides, we also discover that starting point bias does exist in this dataset.