Abrupt and persistent reconfiguration of ecosystem’s structure and function has been observed on a wide variety of ecosystems worldwide. While scientist believe that such phenomena could become more common and severe in the near future, little is known about the patterns of regime shifts’ causes and consequences for human well-being. This thesis aims to assess global patterns of regime shifts in social-ecological systems. A framework for comparing regime shifts has been developed as well as a public forum for discussing knowledge about regime shifts, namely the regime shift database. The most common drivers and expected impacts on ecosystem services have been identified by studying the qualitative topology of causal networks as well as the statistical properties that explain their emergent patters. Given that long time series data for ecosystems monitoring is rather sparse, and experimenting with ecosystems at the scales required to understand their feedback dynamics is rarely an option; we also proposed an indirect computationally based method for monitoring changes in ecosystem services. I hope the results here presented offer useful guidance for managers and policy makers on how to prioritize drivers or impacts of regime shifts: one take home message is that well-understood variables are not necessary the ones where most managerial efforts need to be taken. I also hope the scientific community rigorously criticize our results, but also acknowledge that when doing theoretical or empirical work, our methods tend to ignore the multi-causal nature of regime shifts. By bringing back multi-causality to the scientific debate, I hope our results offer new avenues for hypothesis exploration and theory development on the human endeavour of understanding Nature. / Transiciones críticas o cambios de régimen en ecosistemas se definen como reconfiguraciones abruptas de su estructura y función. Estos cambios, en ocasiones inesperados, se han documentado en una gran variedad de ecosistemas en todo el planeta. Algunos científicos proponen que en el futuro cercano dichos fenómenos pueden volverse más frecuentes y severos. Sin embargo, sabemos muy poco sobre las causas y consecuencias potenciales para el bienestar humano. El objetivo de esta tesis es evaluar patrones globales de cambios de régimen en sistemas socio-ecológicos. Un marco conceptual para comparar cambios de régimen y un foro público de discusión sobre el estado del arte en su conocimiento fue desarrollado en la base de datos virtual www.regimeshifts.org. Las causas más comunes y los impactos en servicios ecosistémicos más esperados han sido identificados estudiando las propiedades topológicas de redes causales, así como las propiedades estadísticas que explican sus propiedades emergentes. Dado que experimentar con ecosistemas a la escala adecuada para capturar sus mecanismos causales generalmente no es una opción, y dado que la disponibilidad de datos de largo plazo necesarios para monitorear cambios de régimen son la excepción y no la regla, proponemos un método indirecto computacional para monitorear cambios en servicios ecosistémicos. Espero que los resultados sean de utilidad para actores encargados del diseño de políticas o del manejo de ecosistemas, especialmente espero que ofrezcan una guía sobre cómo priorizar causas y consecuencias de estos cambios de régimen: una lección clave es que las variables que mejor entendemos o las que más monitoreamos no son necesariamente aquellas en las que debemos enfocar las estrategias de manejo. También espero que la comunidad científica critique con rigor nuestros resultados, pero a su vez reconozca que tanto el trabajo empírico y teórico como los métodos que comúnmente se utilizan para estudiar cambios de régimen tienden a ignorar su naturaleza multi-causal. Al enfatizar la diversidad de sus causas, espero que los resultados ofrezcan nuevas posibilidades para la exploración de hipótesis y el desarrollo de teorías para entender mejor la Naturaleza. / Abrupt och ihållande omkonfigurering av ekosystems struktur och funktion har observerats i en mängd olika ekosystem världen över. Forskning visar på att dessa fenomen antas bli vanligare och allvarligare inom vår närmsta framtid. Kunskapen kring dessa s.k. regimskiften är dock bristfällig, framförallt kring dess konsekvenser för mänskligt välbefinnande. Denna avhandling syftar till att bedöma globala mönster av regimskiften. Ett ramverk för att jämföra regimskiften, samt ett offentligt forum, “the regime shifts database”, för att främja diskussion och sprida kunskap om regimskiften, har utvecklats. De mest förekommande drivkrafter och effekter på ekosystemtjänster har identifierats genom att studera kvalitativa topologiska och kausala nätverk, samt de statistiska egenskaperna som förklarar deras framväxande mönster. Då långvariga tidsserier av ekosystemövervakning är få, och då de experiment som krävs för att förstå regimskiftens återkopplingsdynamik sällan är möjliga, föreslås också en indirekt beräkningsmetod för övervakning av förändringar i ekosystemtjänster. Resultaten från denna avhandling ämnar ger värdefull vägledning för beslutsfattare om prioriteringsordningen mellan olika typer av drivkrafter och effekter av regimskiften. En viktig slutsats är att gedigen kunskap om en viss variabel inte nödvändigtvis ger området där insatser bör tillsättas. Vidare, genom att föra tillbaka multi-kausalitet till den vetenskapliga debatten, erbjuder avhandlingen nya vägar för hypotesprövning och teoriutveckling inom vår gemensamma strävan att förstå Naturen. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 4: Manuscript.</p>

The aim of this study was to explore how psychosocial lived experiences of taxi drivers explain accident involvement in Uganda. Face to face in-depth semi-structured interviews were conducted with six male taxi drivers who survived accidents while driving and still served as taxi drivers. The sample was identified with purposive and snowball sampling techniques. Ethical considerations were observed during data collection through transcription, analysis to the final compilation. Interpretive phenomenological analysis (IPA) was employed to each participant’s discernment of the specific and general accounts of accident narratives in a bid to make "sense" of their lived worlds as drivers and accident involvement. Three superordinate themes illuminating accidents emerged out of the data: typical routines of taxi drivers; the socio-cultural context; and the taxi drivers’ community. These were discussed based on relevant theories and previous studies as well as pertinent concepts. Considering the study results, typical routines of taxi drivers, driver community factors and social/cultural factors affect each other, these together leave driver-accident involvement inevitable. Categorically such factors include; age, formal education, driving training, driver health status, domestic concerns, significant others, competitive driving / worse-worse, other road users, Impulsive pick and drop-off of passengers, theft, driver stress, state of the road, state of the vehicle among others. Thus behavioural and cognitive remedies are herein suggested towards ameliorative and/or transformative processes of the accident endemic.

This creative project documents the effects of deregulation on the trucking industry. Through the use of DVD, the viewer learns all about the culture of trucking and the way it has changed in the past 30 years since deregulation. In August of 2006, I logged over 4,000 miles speaking with four different drivers. The result is a DVD consisting of a documentary, video short stories, photo journals, audio recordings and a flash card game, teaching the viewer about the trucking culture. / Department of Telecommunications

The outsourcing of non–core Information and Communication Technology services in the ICT industry has been successfully conducted for many years based on various models and frameworks. Client organisations embark on this for many reasons including cost savings, access to specialised skills and access to global resources to name but a few. This study identified and evaluated the management of outsource agreements between client organisations and suppliers with specific focus on creating an understanding of those factors that has a direct impact on the success of outsource agreements. The primary objective of the research study was to provide a comprehensive management guideline for client organisations embarking on outsource initiatives or planning to renew existing agreements. The secondary objective was to assist service providers with guidance on pitfalls and issues experienced in the management of such agreements and to highlight the lessons learned from the industry at large. The research was conducted by means of a literature study and empirical study. The literature study included background information on outsourcing, outsourcing theories as well as outsource management frameworks. Furthermore, it addressed lessons learned and issues and pitfalls to avoid by service providers. The literature review formed the basis for creating an understanding of those factors that has a direct impact on the success of outsource agreements. Based on the evaluation of the empirical study, it was concluded that client organisations that are planning to embark on the outsourcing or renewal of services need to follow a management framework with a full lifecycle in order to ensure success. The top issues that suppliers need to address are to ensure that a climate of trust exists between them and the client; they need to be as transparent as possible and ensure that they carry extensive business knowledge of the client being serviced. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2012.

The outsourcing of non–core Information and Communication Technology services in the ICT industry has been successfully conducted for many years based on various models and frameworks. Client organisations embark on this for many reasons including cost savings, access to specialised skills and access to global resources to name but a few. This study identified and evaluated the management of outsource agreements between client organisations and suppliers with specific focus on creating an understanding of those factors that has a direct impact on the success of outsource agreements. The primary objective of the research study was to provide a comprehensive management guideline for client organisations embarking on outsource initiatives or planning to renew existing agreements. The secondary objective was to assist service providers with guidance on pitfalls and issues experienced in the management of such agreements and to highlight the lessons learned from the industry at large. The research was conducted by means of a literature study and empirical study. The literature study included background information on outsourcing, outsourcing theories as well as outsource management frameworks. Furthermore, it addressed lessons learned and issues and pitfalls to avoid by service providers. The literature review formed the basis for creating an understanding of those factors that has a direct impact on the success of outsource agreements. Based on the evaluation of the empirical study, it was concluded that client organisations that are planning to embark on the outsourcing or renewal of services need to follow a management framework with a full lifecycle in order to ensure success. The top issues that suppliers need to address are to ensure that a climate of trust exists between them and the client; they need to be as transparent as possible and ensure that they carry extensive business knowledge of the client being serviced. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2012.

This paper presents the results of a focus group study exploring older individuals' perceptions of older drivers. The study extends the stereotype research of Joanisse, Gagnon, and Voloaca (2012b), further investigating the terms used to describe older drivers. Also explored were the ways older adults perceive age versus health in their considerations of driving. Three focus groups (N=24) were conducted with former and current drivers, 64 years and older, living in Asheville, North Carolina. Participants showed positivity in their descriptions of older drivers as "slow" and "cautious" and believed they adapted their driving behavior as aging demanded. Participants showed heterogeneity in their acceptance of the health issues that threatened their continued driving ability. The importance of context in understanding stereotypes of older adults is illustrated. Results are discussed in terms of ingroup/outgroup theory in line with the proposed model.

The aim of this thesis was to examine the extent, and correlates, of self-regulation of driving behaviour among a sample of South Australian older drivers (aged 60 or more). The first of four studies was an analysis of official crash statistics in South Australia over a period of five years. The patterns of crash involvement for South Australian older drivers were found to resemble those reported in the literature for other jurisdictions. Lower levels of crash involvement for older drivers in difficult driving situations (peak hour, rain, darkness) were interpreted as indirect evidence for self-regulation of driving behaviour. The second study involved pilot testing a measure developed specifically for assessing the visual attention of older adults (the Computerised Visual Attention Test - CVAT). The CVAT assesses visual attention by measuring target detection and reaction time for central and peripheral stimuli, and in conditions requiring selective and divided attention. The third study involved assessing the test-retest reliability, construct validity and predictive validity of the CVAT. It was concluded that the CVAT is a reliable measure of abilities including, but not restricted to, attention, and that it is correlated with on-road driving ability. The fourth study involved an examination of the driving behaviour and attitudes of 104 drivers aged over 60, with avoidance of difficult driving situations providing an index of self-regulation. These drivers also completed a battery of tests measuring psychological factors, vision, physical functioning, various cognitive abilities, and attention (the CVAT). Ninety participants additionally completed an on-road assessment of driving ability. It was found that older drivers most often avoided reverse parallel parking and driving at night in the rain, while driving alone was avoided least often. Measures of visual attention, medication use and visual acuity were most predictive of levels of self-regulation, while poorer driving ability was only associated with avoidance of a small number of specific situations. Functional deficits related to poorer driving ability but not to self-regulation included poorer contrast sensitivity, speed of information processing and spatial memory. Such deficits could identify drivers who may need to restrict their driving more than they do. / Thesis (Ph.D.)--Department of Psychology, 2004.

This dissertation is dedicated to the problem of device driver reliability. Software defects in device drivers constitute the biggest source of failure in operating systems, causing significant damage through downtime and data loss. Previous research on driver reliability has concentrated on detecting and mitigating defects in existing drivers using static analysis or runtime isolation. In contrast, this dissertation presents an approach to reducing the number of defects through an improved device driver architecture and development process. In analysing factors that contribute to driver complexity and induce errors, I show that a large proportion of errors are due to two key shortcomings in the device-driver architecture enforced by current operating systems: poorly-defined communication protocols between drivers and the operating system, which confuse developers and lead to protocol violations, and a multithreaded model of computation, which leads to numerous race conditions and deadlocks. To address the first shortcoming, I propose to describe driver protocols using a formal, state-machine based, language, which avoids confusion and ambiguity and helps driver writers implement correct behaviour. The second issue is addressed by abandoning multithreading in drivers in favour of a more disciplined event-driven model of computation, which eliminates most concurrency-related faults. These improvements reduce the number of defects without radically changing the way drivers are developed. In order to further reduce the impact of human error on driver reliability, I propose to automate the driver development process by synthesising the implementation of a driver from the combination of three formal specifications: a device-class specification that describes common properties of a class of similar devices, a device specification that describes a concrete representative of the class, and an operating system interface specification that describes the communication protocol between the driver and the operating system. This approach allows those with the most appropriate skills and knowledge to develop specifications: device specifications are developed by device manufacturers, operating system specifications by the operating system designers. The device-class specification is the only one that requires understanding of both hardware and software-related issues. However writing such a specification is a one-off task that only needs to be completed once for a class of devices. This approach also facilitates the reuse of specifications: a single operating-system specification can be combined with many device specifications to synthesise drivers for multiple devices. Likewise, since device specifications are independent of any operating system, drivers for different systems can be synthesised from a single device specification. As a result, the likelihood of errors due to incorrect specifications is reduced because these specifications are shared by many drivers. I demonstrate that the proposed techniques can be incorporated into existing operating systems without sacrificing performance or functionality by presenting their implementation in Linux. This implementation allows drivers developed using these techniques to coexist with conventional Linux drivers, providing a gradual migration path to more reliable drivers.

Thesis (M.S.)--University of Nevada, Reno, 2007. / "May 2007." Includes bibliographical references (leaves 84-85). Online version available on the World Wide Web.

Thesis (M.Soc.Sc. Psychology)--University of Waikato, 2007. / Title from PDF cover (viewed March 4, 2008) Includes bibliographical references (p. 127-137)