Numerous studies have investigated the relationship between physical activity and physiological health (e.g., Burke et al., 2006; Irwin, 2004). Less attention has been paid to the contribution of physical activity on psychological well-being (Fox et al., 2000), and more specifically eudaimonic well-being, which reflects optimal psychological functioning and development at ones maximum potential (Ryff, 1989, 1995). This study investigated the role that health-enhancing physical activity (HEPA; any form of physical activity that benefits health and functional capacity; Miilunpalo et al., 2000) plays in eudaimonic well-being, which Ryff conceptualizes in terms of six dimensions: (1) Autonomy (i.e., being self-determined and independent); (2) Environmental Mastery (i.e., having a sense of mastery and competence in managing the environment); (3) Personal Growth (i.e., having a feeling of continued development); (4) Positive Relations with Others (i.e., having warm, satisfying, and trusting relationships with others); (5) Purpose in Life (i.e., having goals and a sense of direction in life); and, (6) Self-acceptance (i.e., possessing a positive attitude toward the self).<p> Employing Ryffs (1989, 1995) perspective of eudaimonic well-being, this study explored whether or not experiencing eudaimonia during HEPA moderates the relationship between HEPA and eudaimonic well-being. Additionally, it explored whether or not the relationship between experiencing eudaimonia during HEPA and eudaimonic well-being is mediated by basic need satisfaction. Undergraduate university students (N = 524; Mage = 20.7 years) completed an online survey including the Scales of Psychological Well-Being (Ryff & Keyes, 1995), the Short Questionnaire to Assess Health-enhancing Physical Activity (Wendel-Vos et al., 2003), the Hedonic and Eudaimonic Motives for Activity scale (Huta & Ryan, 2008), and the Psychological Need Satisfaction in Exercise Scale (Wilson, Rogers, et al., 2006). While level of HEPA was not significantly related to eudaimonic well-being (r = .05, p = .24), experiencing hedonia during HEPA (i.e., enjoying oneself, experiencing pleasure; r = .40, p < .01), experiencing eudaimonia during HEPA (r = .37, p < .01), and basic need satisfaction (r = .46, p < .01) were significantly related to eudaimonic well-being. Although experiencing eudaimonia during HEPA did not moderate the relationship between HEPA and eudaimonic well-being, experiencing eudaimonia during HEPA accounted for a significant 2.2% unique variance in eudaimonic well-being beyond HEPA and experiencing hedonia during HEPA (the full model accounted for a significant 18.2% of the variance in eudaimonic well-being).<p> Furthermore, the data were consistent with a model of partial mediation in that basic need satisfaction partially accounted for the relationship between experiencing eudaimonia during HEPA and eudaimonic well-being, supporting the proposition put forth by Ryan et al. (2008) that positive psychological well-being is a result of eudaimonic living that facilitates the satisfaction of our basic psychological needs. Findings from this study suggest that what appears to be significant in the relationship between HEPA and eudaimonic well-being is not the level of activity, but rather what is experienced during the activity. Future research may explore the directionality of the relationship by examining the extent to which eudaimonic well-being influences what is experienced during activity.

Cryptographic credentials allow user authorizations to be granted and verified. and have such applications as e-Passports, e-Commerce, and electronic cash. This thesis proposes a privacy protecting approach of binding biometrically derived keys to cryptographic credentials to prevent unauthorized lending. Our approach builds on the 2011 work of Adams, offering additional benefits of privacy protection of biometric information, generality on biometric modalities, and performance. Our protocol integrates into Brands’ Digital Credential scheme, and the Anonymous Credentials scheme of Camenisch and Lysyanskaya. We describe a detailed integration with the Digital Credential Scheme and sketch the integration into the Anonymous Credentials scheme. Security proofs for non-transferability, correctness of ownership, and unlinkability are provided for the protocol’s instantiation into Digital Credentials. Our approach uses specialized biometric devices in both the issue and show protocols. These devices are configured with our proposed primitive, the fuzzy ex-tractor indistinguishability adaptor which uses a traditional fuzzy extractor to create and regenerate cryptographic keys from biometric data and IND-CCA2 secure en-cryption protect the generated public data against multiplicity attacks. Pedersen commitments are used to hold the key at issue and show time, and A zero-knowledge proof of knowledge is used to ensure correspondence of key created at issue-time and regenerated at show-time. The above is done in a manner which preserves biometric privacy, as and delivers non-transferability of digital credentials. The biometric itself is not stored or divulged to any of the parties involved in the protocol. Privacy protection in multiple enrollments scenarios is achieved by the fuzzy extractor indistinguishability adapter. The zero knowledge proof of knowledge is used in the showing protocol to prove knowledge of values without divulging them.

This thesis summarises research focused on the requisites required to implement improvement initiatives successfully. Processes used to enhance supply chain performance initiatives are examined. The core hypothesis is that a preconditioning programme provides support for progressive organisations, irrespective of size or position in the supply chain. An interpretation matrix developed as a result of action research with M E Ltd was tested with NP Ltd and its suppliers. During search conferences the matrix was found to add value by serving as a common platform to record then compare observations and agree a common understanding between participants. Based on qualitative descriptions of training and learning in organisations from the 1950s to the 1970s, Barrington's model has three levels: 'systematic approach' predominating in the 1950s, 'appraisal approach' developed extensively in the 1960s and an 'attitude to continuous improvement' that was promoted after the 1970s fuel crises. This model was used as the basis for selecting collaborating establishments. The literature review concludes that conventional supplier development has the attributes of the systematic approach, which is considered the least effective level. M E Ltd was considering introducing appraisal, had few attributes of the systematic approach, and had an attitude for continuous improvement. A company specific survey was undertaken that led to a series of remedial actions which were identified as a preconditioning programme prior to supplier development. NP Ltd selected leaders by attitude, had institutionalised appraisals and once the core group was established, trained employees with systematic techniques. AAP Ltd had the attitude and systematic techniques, yet did not have appraisal systems. Principal conclusions of this are: · These case studies suggest companies can have any two of Barrington's levels. As a result, an alternate depiction of Barrington’s model is suggested. · The cases indicate that preconditioning can occur within a company, from customer to suppliers and from suppliers to customer. · The cases suggest product development roadmap stability as a root cause for negative effects to the relationship between customer and supplier.

We propose a scheme for outsourcing Private Information Retrieval (PIR) to untrusted servers while protecting the privacy of the database owner as well as that of the database clients. We observe that by layering PIR on top of an Oblivious RAM (ORAM) data layout, we provide the ability for the database owner to perform private writes, while database clients can perform private reads from the database even while the owner is offline. We can also enforce pricing and access control on a per-record basis for these reads. This extends the usual ORAM model by allowing multiple database readers without requiring trusted hardware; indeed, almost all of the computation in our scheme during reads is performed by untrusted cloud servers. Built on top of a simple ORAM protocol, we implement a real system as a proof of concept. Our system privately updates a 1 MB record in a 16 GB database with an average end-to-end overhead of 1.22 seconds and answers a PIR query within 3.5 seconds over a 2 GB database. We make an observation that the database owner can always conduct a private read as an ordinary database client, and the private write protocol does not have to provide a "read" functionality as a standard ORAM protocol does. Based on this observation, we propose a second construction with the same privacy guarantee, but much faster. We also implement a real system for this construction, which privately writes a 1 MB record in a 1 TB database with an amortized end-to-end response time of 313 ms. Our first construction demonstrates the fact that a standard ORAM protocol can be used for outsourcing PIR computations in a privacy-friendly manner, while our second construction shows that an ad-hoc modification of the standard ORAM protocol is possible for our purpose and allows more efficient record updates.

This thesis extends previous work on navigational aidingof groups of aircraft, primarily intended for the fighter SAAB JAS 39 Gripen,as long as an aircraft gets GPS signals, it is easy to estimate position, but theGPS is relatively easy to jam, rendering alternative methods of positioning necessary.To use internal sensors measuring accelerations and angular velocities is agood replacement on short terms, but gives a drift in positioning over longer timeperiods. To resolve these issues, we review different possibilities to improve navigation performance bycombining measurement data from different aircraft using a consensus filter.We show that the performance canbe improved by using measurements of distance and angles to other aircraft withinthe group in a distributed filter.The filter is implemented in Matlab and evaluated in different scenarios, and this Extended Kalman-Consensus Filter (EKCF) is compared to a previously proposed solution using an Extended Kalman Filter (EKF). / Det här examensarbetet vidareutvecklar en befintlig algorithm för navigeringsstöttningav grupper av flygplan, främst inriktat på SAAB JAS 39 Gripen. Genomatt kombinera mätdata från olika flygplan kommer vi gå igenom hur man kanförbättra prestanda genom applicering av consensusfilter. Så länge ett plan harGPS-signal är positionering enkelt. Dock är den relativt lätt att störa ut, vilketgör alternativa lösningar för positionering nödvändiga. Att använda interna sensorersom mäter accelerationer och vinkelhastigheter fungerar utmärkt på kortsikt, men ger en drift över en längre tidsperiod.För att lösa de här problemen utvärderar vi olika möjligheter att förbättra navigationsprestandangenom att kombinera mätdata från olika flygplan med hjälpav ett consensusfilter. Vi visar att prestandan kan förbättras genom att användadistans- och vinkelmätningar inom gruppen med distribuerade filter. Filtret ärimplementerat i Matlab med olika scenarier och jämför Extended Kalman-ConsensusFilter (EKCF) med den föregående lösningen med ett Extended Kalman Filter (EKF).

Cryptographic credentials allow user authorizations to be granted and verified. and have such applications as e-Passports, e-Commerce, and electronic cash. This thesis proposes a privacy protecting approach of binding biometrically derived keys to cryptographic credentials to prevent unauthorized lending. Our approach builds on the 2011 work of Adams, offering additional benefits of privacy protection of biometric information, generality on biometric modalities, and performance. Our protocol integrates into Brands’ Digital Credential scheme, and the Anonymous Credentials scheme of Camenisch and Lysyanskaya. We describe a detailed integration with the Digital Credential Scheme and sketch the integration into the Anonymous Credentials scheme. Security proofs for non-transferability, correctness of ownership, and unlinkability are provided for the protocol’s instantiation into Digital Credentials. Our approach uses specialized biometric devices in both the issue and show protocols. These devices are configured with our proposed primitive, the fuzzy ex-tractor indistinguishability adaptor which uses a traditional fuzzy extractor to create and regenerate cryptographic keys from biometric data and IND-CCA2 secure en-cryption protect the generated public data against multiplicity attacks. Pedersen commitments are used to hold the key at issue and show time, and A zero-knowledge proof of knowledge is used to ensure correspondence of key created at issue-time and regenerated at show-time. The above is done in a manner which preserves biometric privacy, as and delivers non-transferability of digital credentials. The biometric itself is not stored or divulged to any of the parties involved in the protocol. Privacy protection in multiple enrollments scenarios is achieved by the fuzzy extractor indistinguishability adapter. The zero knowledge proof of knowledge is used in the showing protocol to prove knowledge of values without divulging them.

The purpose of this research has been to understand the profession and discipline of investor relations in publicly listed entities in South Africa, and their response to the opportunities and threats of using social media as another channel of communication. These responses include the rationale, and strategies pursued and practised in order to enhance investor relations. To gain an understanding of whether the investor relations practitioners see the role of social media to enhance their programmes, a qualitative research with an exploratory design was conducted on thirteen organisations listed on the Johannesburg Securities Exchange main board with a market capitalisation amount exceeding R4.5 billion per annum. It was discovered that investor relations was formalised in the form of strategies formulated and the internal and JSE-regulated practices performed suggest that they take pursuit of investor relations seriously. Furthermore, despite the widespread usage or social media for customer engagement purpose, investor relations practitioners do not yet regard social media as a tool that could supplement disclosure requirements as well provide non financial information about companies. This purpose is currently being served by the dedicated investor relations websites only. Based on findings made, investor willingness will also drive the use of social media. Some of the recommendations made include engaging the JSE for the endorsement of social media, implementation of maturity models and engaging investors on their information needs when making investment decisions. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

Nowadays, housing and urban regeneration policies are becoming crucial to ensuring that the locations in any city are ‘top quality’ and distinctively attractive. This is also essential for the residential profile of the city and its region. Not only the character and functioning of the housing market, and the match between demand and supply, but also the quality of the built environment, the distinctive architecture, the urban layout and the state of environmental conditions in general are important in distinguishing one city-region from others. Diversified neighbourhoods and well-functioning housing markets can be attractive for people working in the creative knowledge economy. This implies that it may be necessary to develop tailored housing and urban renewal policies to ensure attractiveness.

The subject of this dissertation is the construction of privacy-enhancing technologies (PETs) for transparency logging, a technology at the intersection of privacy, transparency, and accountability. Transparency logging facilitates the transportation of data from service providers to users of services and is therefore a key enabler for ex-post transparency-enhancing tools (TETs). Ex-post transparency provides information to users about how their personal data have been processed by service providers, and is a prerequisite for accountability: you cannot hold a controller accountable for what is unknown. We present three generations of PETs for transparency logging to which we contributed. We start with early work that defined the setting as a foundation and build upon it to increase both the privacy protections and the utility of the data sent through transparency logging. Our contributions include the first provably secure privacy-preserving transparency logging scheme and a forward-secure append-only persistent authenticated data structure tailored to the transparency logging setting. Applications of our work range from notifications and deriving data disclosures for the Data Track tool (an ex-post TET) to secure evidence storage. / The subject of this dissertation is the construction of privacy-enhancing technologies (PETs) for transparency logging, a technology at the intersection of privacy, transparency, and accountability. Transparency logging facilitates the transportation of data from service providers to users of services and is therefore a key enabler for ex-post transparency-enhancing tools (TETs). Ex-post transparency provides information to users about how their personal data have been processed by service providers, and is a prerequisite for accountability: you cannot hold a controller accountable for what is unknown. We present three generations of PETs for transparency logging to which we contributed. We start with early work that defined the setting as a foundation and build upon it to increase both the privacy protections and the utility of the data sent through transparency logging. Our contributions include the first provably secure privacy-preserving transparency logging scheme and a forward-secure append-only persistent authenticated data structure tailored to the transparency logging setting. Applications of our work range from notifications and deriving data disclosures for the Data Track tool (an ex-post TET) to secure evidence storage.

The world of sport has recently been inundated by stories of doping. These reports are not limited to a select few individuals or sports, but seemingly are spread across sports. At first, it was mostly members of the sports community voicing their discontent, but soon actors outside of the sports community, such as government committees, became interested. Anti-doping policies were created to reduce doping; however, these policies were created independently of government and vary in effectiveness. The most visible variances are between professional and amateur sports. Accordingly, this paper investigates why there is variation between professional and amateur anti-doping policies. This investigation is done in a qualitative fashion and employs the Most Similar System of Design (a comparative method) to identify that factors result in the differences. The paper also contributes to the field by creating and organizing the ethics of doping. Furthermore, it compares the various existing approaches to anti-doping policy by analysing the anti-doping policies of the PGA, IOC, WADA, and the MLB. Subsequently, the paper identifies seven obstacles facing anti-doping regulators and identifies new policy tools that could aid anti-doping policies. Finally, it closes with policy recommendations for the future. This paper is comprehensive: it introduces the topic of anti-doping, the subsequent definitions, explains the ethical considerations, answers why there is variation between professional and amateur anti-doping policies, and provides policy recommendations.