Many problems in geometric measure theory are centered around finding conditions and structures on a set to guarantee that its distance set must be large. Two notions of structure that are of importance in this work are Hausdorff dimension and thickness. Recent progress has been made on generalizing the notion of thickness so part of this work also generalizes previous results using this new upgraded version of thickness. We also show why a famous conjecture about distance sets does not hold on the real line and thus, why this conjecture needs to happen in higher dimensions. Furthermore, we give explicit distance set and thickness calculations for a special class of self-similar sets. / Master of Science / Part of the study of geometric measure theory is centered around creating interesting structures to place on a set and determining what sort of threshold on that structure allows you to guarantee that some interesting geometric property exists for that set. An example of this is determining when you can guarantee that a set contains many unique distances between elements in that set. This work presents various types of structures that help to investigate the problem of when you can guarantee that a set has the previously mentioned geometric property.

Yes / This communication complements the DEA model proposed by Lovell and Pastor (1999), by incorporating both positive and negative criteria in the model. As such, we propose a DEA model, known as pure DEA, using a directional distance function approach.

No / Measuring piston crown temperature and pressure during engine development cycle is paramount. This paper presents a new development in short distance telemetry system which includes an on board power generation device. A mechatronic data acquisition system is developed whereby signal conditioning is performed by a module inside the piston and the signal passed to a Bluetooth transmitter module for wireless telemetry to a Bluetooth receiver located in very close proximity, connected to an external host PC. The Data Acquisition Bluetooth module integrates a microcontroller that reads the conditioned sensor signal and performs any other required functionality. The microcontroller firmware includes a server that collates the data and transmits them via Bluetooth to the host PC to display via a client interface. An independent power supply consisting of a rotor incorporating NdFeB magnets and a wire wound stator. As the crankshaft rotates the rotor induces an AC voltage into the stator. A rectifying circuit converts the AC voltage into a regulated DC output voltage that drives the signal conditioning and embedded Bluetooth circuits.

The purposes of this study were to: (a) determine the professional development preferences of educators in a selected school district, (b) discover to what extent and under what circumstances these educators desired the use of Web-based distance education for professional development purposes, and (c) discover the obstacles to implementation of Web-based instruction professional development within the school district. In addition, demographic and informational data thought to be pertinent were solicited. A survey instrument developed for this study was administered to 1,843 site-based educators; 1,455 (78.95%) surveys from all (N=39) of the targeted schools were returned. Analyses of the data provided by respondents indicated the following major findings: (a) 90.2% preferred to use district-provided in services for recertification training; (b) 64% reported a high computer and Internet comfort level; (c) 74% preferred learning with peers over solitary training; (d) 44.5% favored traditional in service delivery over Web-based instruction; (e) appropriate subject matter was deemed the most important element in the selection of training, followed by training when needed, stipends, training location, and training with peers, respectively; (f) 61% indicated an interest in utilizing Web-based instruction for recertification purposes and 61.3% for required subjects; (g) 65.1% would use Web-based instruction if a menu of practical topics were offered; and (h) 62.7% would use Web-based instruction if training was provided. Inadequate marketing of online courses and user fear of insufficient instructor assistance (26.7%) were found to be barriers to implementation. No statistical significance was found between chosen demographic data (age, gender, grade level, and job category) and desire for Web-based instruction. Training in the use of technology and Web-based instruction was deemed desirable prior to the implementation of online delivery.

No description available.

As more universities begin to offer distance education classes, advances in current methods of delivering classroom information must be introduced. At present, universities use two different methods for distance education. The first is text-based web pages, which due to bandwidth restrictions are generally unable to display complex multimedia information. The second method is to videotape lectures and distribute the tapes to distant sites. While this does a reasonable job of simulating a classroom, the cost associated with producing and distributing the videos and the delay involved in distribution makes this system unattractive. This thesis presents a method for compressing the classroom video to a smaller size so that the lecture can be rebroadcast over the Internet without losing classroom information. In addition, methods will be demonstrated for automatically extracting various types of information from a videotaped lecture; this will result in a more interactive lecture than a simple videotape would provide.

Titre de l'écran-titre (visionné le 16 octobre 2023) / La technologie de chauffage et de refroidissement urbain est l'une des solutions prometteuses pour réduire la consommation d'énergie afin d'atténuer les effets des changements climatiques. La tendance du développement des systèmes de chauffage et de refroidissement urbains est d'abaisser la température d'alimentation. Ainsi, les réseaux thermiques seraient en mesure de réduire les déperditions de chaleur et d'augmenter sensiblement le nombre de sources de chaleur récupérables. Cependant, la baisse de la température de fonctionnement du quartier peut entraîner divers problèmes. Le premier problème concerne les quartiers avec des bâtiments anciens dont la température pour le chauffage peut être élevés (80°C) alors que la température du réseau de chauffage urbain de 4ème génération est d'environ 50°C (30-70°C pour la 4ème génération). Bien que l'abaissement de la température du réseau puisse augmenter l'efficacité des centrales d'approvisionnement et réduire la perte de chaleur à travers le réseau, les conséquences connexes telles que l'augmentation des frais d'exploitation et l'augmentation des émissions de GES causées par l'augmentation de la consommation d'électricité des pompes à chaleur distribuées devraient être considéré. Par conséquent, la température d'alimentation doit être optimisée. Pour cette raison, la première étape de ce projet s'est concentrée sur la température d'alimentation optimale pour un quartier avec une demande de chauffage à haute température. Ce projet propose un nouveau cadre d'optimisation multi-objectifs pour déterminer la température d'alimentation en temps réel pour le chauffage urbain à basse température avec des pompes à chaleur distribuées. Les résultats montrent que le cadre proposé peut effectivement réduire les coûts et les émissions, mais la viabilité du système dépend fortement du type de combustible (c.-à-d. copeaux de bois ou gaz naturel), du prix de l'électricité, du facteur d'émission de l'électricité, du poids relatif des coûts et des émissions dans la fonction objective. Dans l'étude de cas avec des coûts d'électricité et des émissions typiques pour le Québec (Canada), la température de fonctionnement moyenne pourrait être réduite à 42 et 66°C selon le type de chaudières dans le système. Alors que les émissions étaient toujours plus faibles qu'avec un réseau conventionnel, les coûts d'exploitation pouvaient être plus élevés (avec une chaudière à copeaux de bois) ou plus bas (avec une chaudière au gaz naturel). Ces travaux peuvent contribuer au déploiement de réseaux basse température performants. Le deuxième problème concerne les nouveaux quartiers avec une demande simultanée de chauffage et de refroidissement. Dans ce cas, quelle est la combinaison et la taille optimales des systèmes à basse température compte tenu des facteurs économiques? Le réseau de chauffage et de refroidissement urbains de cinquième génération (5GDHC en anglais) offre une solution efficace pour les quartiers ayant des demandes simultanées de chauffage et de refroidissement. Cependant, la recherche sur les systèmes de chauffage et de refroidissement urbains de 5ème génération en est à ses débuts. Ce deuxième volet proposait un nouveau système de chauffage et de refroidissement urbains de 5ème génération assistés par le solaire hybride photovoltaïque-thermique avec stockage géothermique. Une plateforme décisionnelle de conception et d'exploitation de ce nouveau système est proposée sur la base de l'optimisation. L'optimisation minimise le coût global du cycle de vie en tenant compte des investissements en capital et de remplacement dans l'équipement de district, ainsi que des frais d'exploitation grâce à une conception et une exploitation optimisée du 5GDHC. Une analyse de sensibilité globale est utilisée pour réduire les dimensions de l'optimisation, et les résultats indiquent qu'une optimisation de dimension réduite permet d'obtenir des résultats similaires à une optimisation de dimension complète tout en économisant du temps de calcul. Notre étude montre que même dans les régions où les prix de l'électricité sont bas, comme le Québec, les investissements en capital dans les pompes à chaleur, les forages géothermiques et les systèmes photovoltaïques/thermiques (PVT) peuvent être récupérés à la fin de la durée de vie du projet. L'électricité peut être économisée à plus de 50% pour le nouveau système. Sur la base de l'optimisation, le nouveau système est comparé à un système sans stockage géothermique et 5GDHC avec stockage géothermique mais sans systèmes solaires sur la base d'évaluations économiques du cycle de vie. L'investissement en capital des pompes à chaleur, des forages géothermiques et des systèmes photovoltaïques/thermiques (PVT) peut être remboursé à la fin de la durée de vie du projet. De plus, les systèmes géothermiques peuvent augmenter la récupération de la chaleur résiduelle et de l'énergie solaire. Le 5GDHC à assistance d'hybride photovoltaïque-thermique solaire avec stockage géothermique a surpassé les systèmes sans système solaire ou les systèmes sans stockage géothermique. Les réseaux 5GDHC modifient les interactions énergétiques entre les individus du quartier tout en permettant l'interaction énergétique entre les prosommateurs afin que l'ensemble du quartier puisse bénéficier de l'amélioration de l'efficacité énergétique. La coordination des interactions énergétiques dans un tel système est un problème complexe, généralement résolu par une optimisation centralisée. En plus des problèmes de confidentialité pour les prosommateurs, l'optimisation centralisée peut s'avérer trop difficile à résoudre pour les grands systèmes 5GDHC et ne peut pas établir une répartition des bénéfices entre les prosommateurs. Ceci introduit le troisième problème : pour les individus, comment le bénéfice tiré de l'ensemble du quartier est-il réparti entre les prosommateurs ? En d'autres termes, à quoi ressemble le marché de l'énergie pour ce nouveau système énergétique de quartier ? Ce volet développe un cadre communautaire de marché transactionnel de l'énergie basé sur l'optimisation distribuée de 5GDHC. L'optimisation est basée sur la méthode des multiplicateurs à direction alternée proximale de Jacobi. L'approche repose sur des interactions itératives entre le coordinateur de réseau et les prosommateurs, les premiers ajustant le prix interne de l'énergie thermique et les seconds adaptant leur demande de chauffage et de refroidissement. La méthode proposée a permis d'ajuster dynamiquement le prix interne de l'énergie thermique et la demande des prosommateurs tout en tenant compte de leur insatisfaction thermique. En facilitant le fonctionnement du 5GDHC, ce travail pourrait contribuer à leur mise en œuvre pratique dans le futur. En résumé, ce projet a atteint les trois sous-objectifs suivants : 1) Ce projet a proposé une méthode d'optimisation et d'abaissement de la température du réseau thermique pour un quartier demandant une température élevée pour le chauffage à l'aide de pompes à chaleur distribuées. 2) Ce projet a proposé une nouvelle plate-forme décisionnelle basée sur l'optimisation de la conception et de l'exploitation des nouveaux systèmes de chauffage et de refroidissement urbains hybrides photovoltaïques-thermiques de 5e génération à assistance solaire. 3) Un concept de marché de l'énergie pour ordonnancer la demande thermique des prosommateurs distribués pour le 5GDHC. / District heating and cooling technology is one of the most promising solutions for reducing energy consumption and thus fight climate change. The trend of developing district heating and cooling systems is to lower the supply temperature. As such, thermal networks would be able to abate heat losses and substantially increase the number of recoverable heat sources. However, lowering down the operational temperature of the district may case the several problems. The first problem is for district with old buildings whose temperature requirement for space heating may be high (75°C) while the temperature of the network of 4ᵗʰ generation district heating is around 50°C (30-65°C for 4th generation). Although lowering the temperature of network can increase the efficiency of the supply plants and reduce the heat loss through the network, the related consequence such as increasing operational fees, and increasing GHG emissions caused by the increasing electricity consumption of the distributed heat pumps should be considered. Therefore, the supply temperature should be optimized. Therefore, the first step of this project focused on the optimal supply temperature for district with high temperature heating demand. This project proposes a new multi-objective optimization framework to determine the real-time supply temperature for low-temperature district heating with booster heat pumps. Results show that the proposed framework can indeed reduce costs and emissions, but the viability of the system depends strongly on the fuel type (i.e., wood chips or natural gas), price of electricity, emission factor of electricity, relative weight of costs and emissions in the objective function. In the case-study with typical electricity costs and emissions for Quebec (Canada), the average operating temperature could be reduced to 42 and 66°C depending on the type of boilers in the system. While emissions were always smaller than with a conventional network, operating costs could be higher (with wood chip boiler) or lower (with natural gas boiler). This work can contribute to the deployment of efficient low temperature networks. The second problem is for new district with simultaneous heating and cooling demand. What is the optimal combination and size for the new district with low temperature when considering economic factors? The Fifth Generation District Heating and Cooling (5GDHC) network offers an efficient solution for districts with simultaneous heating and cooling demands. However, research of the 5ᵗʰ generation district heating and cooling systems is in its early stage. This project proposed a novel hybrid photovoltaic-thermal solar-assisted 5ᵗʰ generation district heating and cooling systems with geothermal storage. A decision-making platform for design and operation for this new system is proposed based on optimization. The optimization minimizes the overall lifecycle cost by considering capital and replacement investments in district equipment, and operational fees through optimized design and operation of 5GDHC. A global sensitivity analysis is used to reduce the dimension of optimization, and the results indicate that a reduced-dimension optimization can achieve similar results as a full-dimension optimization while saving computational time. Our study shows that even in regions with low electricity prices, such as Quebec, the capital investments in heat pumps, geothermal boreholes, and photovoltaic/thermal (PVT) systems can be recovered by the end of the project's lifetime. The electricity can be saved up to 50% for the new system. Based on the optimization, the new system is compared with hybrid photovoltaic-thermal solar-assisted 5ᵗʰ generation district heating and cooling system without geothermal storage and 5GDHC with geothermal storage but without solar systems based on economic life cycle assessments. The capital investment of the heat pumps, geothermal boreholes and photovoltaic/thermal (PVT) systems can be paid back at the end of the lifetime of the project. Additionally, geothermal systems can increase the recovery of the waste heat and solar energy. The hybrid photovoltaic-thermal solar-assisted 5GDHC with geothermal storage outperformed for systems without solar system or systems without geothermal storage. 5GDHC has changed the energy interactions between individuals in the district while allowing the energy interactions between prosumers so that the whole district can benefit from improved energy efficiency. Coordinating the energy interactions in such a system is a complex problem, typically solved through centralized optimization. In addition to privacy issues for prosumers, centralized optimization can prove too hard to solve for large 5GDHC systems and cannot establish a profit distribution between prosumers. This introduces the third problem: For individuals, how the benefit gained from optimizing the whole district be allocated between the prosumers? In other words, what is the energy market looks like for this new district energy system? This project develops a community-based transactive energy market framework based on distributed optimization of 5GDHC. The optimization is based on the Jacobi-proximal alternating direction method of multipliers. The approach relies on iterative interactions between the network coordinator and the prosumers, the former adjusting the internal price of thermal energy and the latter adapting their heating and cooling demand. The proposed method allowed to dynamically adjust the internal price of thermal energy and the prosumers' demand while considering their thermal dissatisfaction. By facilitating 5GDHC operation, this work could help their practical implementation in the future. To summarize, this project has achieved the following three sub-objectives: 1) This project proposed a method for optimizing and lowering the temperature of the thermal network for district with high temperature demand with help of distributed heat pumps. 2) This project proposed a new decision-making platform based on optimization for design and operation of the new hybrid photovoltaic-thermal solar-assisted 5ᵗʰ generation district heating and cooling systems. 3) A concept of energy market to schedule the thermal demand of distributed prosumers for 5GDHC.

patients and their families. The purpose of the study was firstly, to explore and interpret the meaning of the experiences of critical care nursing students about clinical accompaniment in open distance learning (ODL). This aspect has not been researched before and as such, there is no empirical data about the clinical accompaniment of the critical care-nursing students in ODL. Secondly, to develop guidelines for facilitation of clinical accompaniment in critical care nursing in ODL. A qualitative hermeneutic phenomenological study was conducted. Non-probability purposive sampling was used to select participants to provide information about clinical accompaniment in ODL. Data was obtained through in-depth interviews supplemented by field notes compiled during fieldwork. The study findings revealed that participants regard relationships and communication as important for clinical accompaniment. The distance factor inherent in distance learning was problematic for student’s motivation and support. The presence and visibility of the lecturer was pivotal for the students. Of importance also were the relationships with the managers and colleagues. The perception of participants was that managers of clinical facilities were not as readily accessible as would have been the lecturer. Although negative experiences were described, paradoxically these experiences seemed to have empowered the student to develop survival skills, patience and assertiveness to take action on how to deal with the situation. From the findings the researcher was able to develop guidelines the implementation of which, is hoped to ensure effective clinical accompaniment of critical care nursing students in ODL. / Health Studies / D. Litt. et Phil. (Health Studies)

Notwithstanding challenges facing systems of higher education world-wide, higher education in South Africa has been fundamentally re-engineered since the achievement of democracy in 1994. The University of South Africa (Unisa) emerged as the only dedicated distance education institution and the biggest provider of higher education. Against the background of transformation in higher education policy and practice in South Africa, this study aimed to address the implementation of higher education policy in relation to the provision of distance education in South Africa, with special reference to Unisa. To address the research problem, a literature study investigated theoretical perspectives, recent policy trends in higher education globally and their influence on distance education and the impact of higher education policy development and implementation in South Africa on Open Distance Learning (ODL) provision. A mixed method empirical research design was used to explore how the academic and administrative cohort of top and middle and extended management at Unisa perceive the implementation of higher education policy at their institution in relation to distance education provision. The inquiry comprised two phases: Phase 1, a quantitative component entailed a survey using a self-designed questionnaire. A non-probability purposive sampling strategy was used to select respondents for the survey, and the entire target population (Unisa employees at middle to executive management level) participated. Phase 2, a qualitative component, entailed semi-structured interviews with a purposeful sample: members of top management and two council members. The survey results indicated strong agreement on the need for strategy and planning, more funding and improved levels of service. There was disagreement or ambivalence around sufficient human and infrastructural capacity, the cost of ODL, quality and the efficiency of ICT systems and processes. Four major areas of concern emerged from the interviews: Transformation (the national transformation agenda and mindset change); funding (enrolment planning and capping, the unfunded student issue and salaries); institutional efficiency (strategy, planning, capacity and quality); and the cost of ODL and the need for a dedicated ODL Policy. The study concluded with recommendations to facilitate the enhanced practice and delivery of ODL in South Africa. / Educational Studies

We are at a point in the history of higher education in South Africa when radical changes are occurring in instructional delivery system models. Of increasing significance is a mixed mode of traditional and distance delivery (i.e. Telematic Learning Systems at the PU for CHE). In this changing environment, language lecturers, the persons responsible for developing language modules within various Telematic programmes, remain a key element in the teaching and learning process. However, these lecturers are suddenly expected to make appropriate decisions in terms of distance education technology classification, evaluation, and consequent selection without the necessary knowledge and/or capacity to make effective technological decisions. The purpose of this article is to assist "Lone Ranger" language lecturers, in making pedagogically sound decisions when classifying, evaluating and selecting distance education technologies by: (a) considering technology selection as part of the instructional design process, (b) referring to some reasons for using technology for language learning, (c) focusing on criteria for classifying and evaluating distance education technologies, and by (d) reviewing selected studies in order to indicate the application possibilities of technologies for language teaching and learning. / Thesis (M.A. (English))--Potchefstroom University for Christian Higher Education, 2002