As one of the poorest countries in the world, Tanzania faces various kinds of problems. The housing situation is poor in the whole country, especially in rural areas where the main part of the population lives in mud houses. The report is focused on modern houses and is aimed at finding sustainable low cost solutions to be used as alternatives for existing techniques. The report is based on a field study in the Mamba district, Tanzania during 8 weeks in 2009. The traditional mud houses are poor and do not live up to a decent standard of living. The living conditions are extremely primitive in these houses and pose a health risk to the occupants. Modern houses provide a better standard of living and are good investments for future generations. The building design and technology can be rationalised and improved and building costs can be reduced through alternative methods. There are several ways in which building costs can be reduced. Focus should be on using local materials to minimise expensive transport costs. Cement is the single most expensive building material and should be replaced by other materials where possible. However, it is important that sustainability of the construction is not impaired. In the long term, it is better to invest in proper sustainable building structures even if the costs will increase. This study has resulted in sustainable low cost alternatives to the current building technology that the local builders can benefit from. Tradition is strong in Tanzania and changes may take long to implement. The alterations suggested and discussed in this report can be considered as a good basis for development of the current building design and technology in the Mamba district.

In the high voltage grid, voltage measurements are made in dedicated voltage-transformers. These devices are expensive and insulation failures could impact directly on the system, and even cause a power outage. A non-contact measurement technique, on the other hand, does not require a connection to the conductors, and the sensors can therefore be much cheaper by avoiding the need for high voltage insulation. A capacitive coupling between three measurement electrodes, close to ground, and a high voltage three phase conductor system is used to model and measure the electric field and thereby determine the potentials of the conductors. A 2D-model is used for simulations, where the sensors are modeled as ideal, the conductors are modeled in an infinite wire approximation, and the ground plane is approximated as a perfect conductor. For non-ideal sensors a transfer function from the potentials on the measurement equipment to the potentials on the conductors is derived as a lumped-circuit model. The L2-norm errors for the amplitude and the phase in the reconstructed signals are calculated and measured for various sensor distances. Simulations show that the sensor distance should not be larger than the conductor distance to mitigate the erroneous effects from distance uncertainties. The optimal sensor distance depends on the quota between the height from the sensors to the conductors and the conductor distance. Measurements show, in accordance with the theory, that the sensor distance should not be larger than the conductor distance. To reduce the amplitude and phase shift errors the sensors should be placed close to the ground. For applied load resistances there is a tradeoff between amplitude- and phase shift errors. Additionally, higher load resistances attenuate higher frequencies. Measurements have verified that this technique is capable of detecting high harmonics and transients. The relatively low cost and the movability makes this method highly applicable for quick diagnostics on many locations in a grid, where the data can be evaluated on-site using computer based scripts. / I kraftnät utförs idag högspänningsmätningar av spänningstransformatorer. Dessa är dyra, och isolationsproblem  kan ha en direkt effekt på kraftnätet, och till och med skapa strömavbrott. En beröringsfri mätmetod, å andra sidan, kräver ingen direkt koppling mellan mätutrustningen och ledarna. Sensorerna kan därmed bli billigare eftersom de inte behöver högspänningsisoleras. En kapacitiv koppling mellan tre stycken mätelektroder, placerade nära jordplanet, och ett högspänt trefasledarsystem  används för att modellera och mäta det elektriska fältet och därigenom bestämma ledarnas potentialer. En 2D-modell används för simuleringar, där sensorerna modelleras som ideala, ledarna modelleras enligt en raktrådsapproximation (oändligt långa raka ledare), och jordplanet approximeras vara en perfekt ledare med oändlig utsträckning. För icke-ideala sensorer härleds en överföringsfunktion från den uppmätta potentialen på mätutrustningen till ledarnas potentialer som en analog kretsmodell. L2-norm-felen för amplitudfel och fasfel för de rekonstruerade signalerna beräknas och mäts för olika sensoravstånd. Simuleringar visar att sensoravståndet inte bör vara större än ledaravståndet för att dämpa felinverkande effekter från osäkerheter i avståndsuppskattningar. Det optimala sensoravståndet beror på kvoten mellan höjden från sensorerna till ledarna och ledaravståndet. Mätningar visar, i enlighet med teorin, att sensoravståndet inte bör vara större än ledaravståndet. För att reducera amplitud- och fasfel bör sensorerna placeras nära jordplanet. För påkopplade lastresistanser gäller att det är en byteshandel mellan amplitud- och fasfel. För övrigt gäller att högre lastresistanser dämpar högre frekvenser. Mätningar verifierar att denna teknik är kapabel att detektera höga frekvenser och transienter. Den relativt låga kostnaden och metodens rörlighet gör att den kan appliceras för snabbdiagnostik på många punkter i ett kraftnät, där det insamlade datat kan utvärderas på plats med hjälp av datorbaserade skript.

The objective of this study is to implement a low-cost smart camera application on a Commercial off the Shelf system that is based on Texas Instrument&rsquo / s DM3730 System on Chip processor. Although there are different architectures for smart camera applications, ARM plus DSP based System on Chip architecture is selected for implementation because of its different core abilities. Beagleboard-XM platform that has an ARM plus DSP based System on Chip processor is chosen as Commercial off the Shelf platform. During this thesis, firstly to start-up the Commercial off the Shelf platform the design steps of porting an embedded Linux to ARM core of System on Chip processor is described. Then design steps that are necessary for implementation of smart camera applications on both ARM and DSP cores in parallel are given in detail. Furthermore, the real-time image processing performance of the Beagleboard-xM platform for the smart camera applications is evaluated with simple implementations.

<p>As one of the poorest countries in the world, Tanzania faces various kinds of problems. The housing situation is poor in the whole country, especially in rural areas where the main part of the population lives in mud houses.</p><p>The report is focused on modern houses and is aimed at finding sustainable low cost solutions to be used as alternatives for existing techniques.</p><p>The report is based on a field study in the Mamba district, Tanzania during 8 weeks in 2009.</p><p>The traditional mud houses are poor and do not live up to a decent standard of living. The living conditions are extremely primitive in these houses and pose a health risk to the occupants. Modern houses provide a better standard of living and are good investments for future generations. The building design and technology can be rationalised and improved and building costs can be reduced through alternative methods.</p><p>There are several ways in which building costs can be reduced. Focus should be on using local materials to minimise expensive transport costs. Cement is the single most expensive building material and should be replaced by other materials where possible. However, it is important that sustainability of the construction is not impaired. In the long term, it is better to invest in proper sustainable building structures even if the costs will increase.</p><p>This study has resulted in sustainable low cost alternatives to the current building technology that the local builders can benefit from. Tradition is strong in Tanzania and changes may take long to implement. The alterations suggested and discussed in this report can be considered as a good basis for development of the current building design and technology in the Mamba district.</p>

The corrosion of steel reinforcement in reinforced concrete structures constitutes an alarming problem. To combat this problem, researchers at the University of Texas at Austin developed two, low-cost, passive, wireless sensors: a threshold, corrosion sensor and an analog conductivity sensor. Today, the basic circuit designs for both sensors are finished and their reliabilities are confirmed. However, multiple problems regarding the durability of the sensors remain. This research project: (a) identifies these problems, (b) proposes enhancements for each type of passive, wireless sensor, (c) tests and evaluates the proposed modifications to the sensors, and (d) proposes potential improvements and areas of research regarding the future development of these two sensors. / text

Residue codes have successfully been used for decades as a low overhead method of arithmetic error detection. This work explores the design space of residue checking for error detection in processors with modern word sizes and technology nodes. The area overheads of detecting arithmetic errors are considered for a variety of processor configurations, ranging from those best suited for embedded processors to those best for high-performance computers. The ultimate goal of this work is to enable the study of low overhead arithmetic error protection and correction in a wider variety of computer architectures than has previously been attempted in a systematic manner. / text

Cost reduction has been and will continue to be a primary driving force in the evolution of hardware design and associated technologies. The objective of this research is to design low-cost signal acquisition systems for characterizing wideband and high-speed signals. As the bandwidth and the speed of such signals increase, the cost of testing also increases significantly; therefore, innovative hardware and algorithm co-design are needed to relieve this problem. In Chapter 2, a low-cost multi-rate system is proposed for characterizing the spectra of wideband signals. The design is low-cost in the sense of the actual component cost, the system complexity, and the effort required for calibration. The associated algorithms are designed such that the hardware can be implemented with low-complexity yet be robust enough to deal with various hardware variations. A hardware prototype is built not only to verify the proposed hardware scheme and algorithms but to serve as a concrete example that shows that characterizing signals with sub-Nyqusit sampling rate is feasible. Chapter 3 introduces a low-cost time-domain waveform reconstruction technique, which requires no mutual synchronization mechanisms. This brings down cost significantly and enables the implementation of systems capable of capturing tens of Gigahertz (GHz) signals for significantly lower cost than high-end oscilloscopes found in the market today. For the first time, band-interleaving and incoherent undersampling techniques are combined to form a low-cost solution for waveform reconstruction. This is enabled by co-designing the hardware and the back-end signal processing algorithms to compensate for the lack of coherent Nyquist rate sampling hardware. A hardware prototype was built to support this work. Chapter 4 describes a novel test methodology that significantly reduces the required time for crosstalk jitter characterization in parallel channels. This is done by using bit patterns with coprime periods as channel stimuli and using signal processing algorithms to separate multiple crosstalk coupling effects. This proposed test methodology can be applied seamlessly in conjunction with the current test methodology without re-designing the test setup. More importantly, the conclusion derived from the mathematical analysis shows that only such test stimuli give unbiased characterization results, which are critical in all high-precision test setups. Hardware measurement results and analysis are provided to support this methodology. This thesis starts with an overview of the background and a literature review. Three major previously mentioned works are addressed in three separate chapters. Each chapter documents the hardware designs, signal processing algorithms, and associated mathematical analyses. For the purpose of verification, the hardware measurement setups and results are discussed at the end of these three chapters. The last chapter presents conclusions and future directions for work from this thesis.

Alberta Health Services (AHS) has introduced e-learning for health professionals to expand their existing training, offer flexible web-based learning opportunities, and reduce training time and cost. This study is designed to evaluate the usability and usefulness of an e-learning module for a patient clinical information system scheduling application. A cost-effective framework for usability evaluation has been developed and conceptualized as part of this research. Low-Cost Rapid Usability Engineering (LCRUE), Cognitive Task Analysis (CTA), and Heuristic Evaluation (HE) criteria for web-based learning were adapted and combined with the Software Usability Measurement Inventory (SUMI) questionnaire. To evaluate the introduction of the e-learning application, usability was assessed in two groups of users: frontline users and informatics consultant users. The effectiveness of the LCRUE, CTA, and HE when combined with the SUMI was also investigated. Results showed that the frontline users are satisfied with the usability of the e-learning platform. Overall, the informatics consultant users are satisfied with the application, although they rated the application as poor in terms of efficiency and control. The results showed that many areas where usability was problematic are related to general interface usability (GIU), and instructional design and content, some of which might account for the poorly rated aspects of usability. The findings should be of interest to developers, designers, researchers, and usability practitioners involved in development of e-learning systems. / Graduate / 0769 / 0984 / 0541 / tdafalla@uvic.ca; tdafalla@gmail.com

The navigation tasks in advanced home robotic applications incorporating reliable revisiting strategies are dependent on very low cost but nevertheless rather accurate localization systems. In this paper a localization system based on the principle of trilateration is described. The proposed system uses only a single small base station, but achieves accuracies comparable to systems using spread beacons and it performs sufficiently for map building. Thus it is a standalone system and needs no odometry or other auxiliary sensors. Furthermore a new approach for the problem of the reliably detection of areas without direct line of sight is presented. The described system is very low cost and it is designed for use in indoor service robotics. The paper gives an overview on the system concept and special design solutions and proves the possible performances with experimental results.

Une approche pour augmenter le débit par longueur d'onde, est d'utiliser la modulation DMT (Discrete Multitone) à haute efficacité spectrale. Le travail présenté dans cette thèse se focalise principalement sur l'optimisation de la consommation en puissance et le coût de la DMT, qui présentent des obstacles majeurs à son industrialisation. Dans ce cadre, nous avons tout d'abord développé des nouvelles techniques permettant d'exclure la symétrie Hermitienne des modulations DMT, réduisant ainsi considérablement la consommation en puissance et le coût du système. Nous avons ensuite proposé un algorithme de compression linéaire asymétrique permettant de réduire la puissance optique de la modulation DMT avec une complexité modérée. Un nouveau modèle comportemental du VCSEL basé sur la caractéristique quasi-statique a été également développé. Nous avons enfin validé expérimentalement les techniques que nous avons proposées. Plusieurs résultats de simulations et de mesures sont ainsi présentés. / A possible approach to maximize the data rate per wavelength, is to employ the high spectral efficiency discrete multitone (DMT) modulation. The work presented in this thesis mainly focuses on optimizing the power consumption and cost of DMT, that are the major obstacles to its market development. Within this context, we have first developed novel techniques permitting to discard the use of Hermitian symmetry in DMT modulations, thus significantly reducing the power consumption and the system cost. We have next proposed an asymmetric linear companding algorithm permitting to reduce the optical power of conventional DCO-OFDM modulation with a moderate complexity. A new VCSEL behavioural model based on the use of the VCSEL quasi-static characteristic was also developed to accurately evaluate the VCSEL impact on DMT modulations. Finally, we have built an experimental system to experimentally validate our proposed techniques. Several simulations and measurement results are then provided.