Customised patient implants : future lifeline of the medical industry

Published ArticleLong-term growth in the additive fabrication industry will come from designs that are difficult, time-consuming, costly, or impossible to produce using standard techniques. Growth will occur with advances in the current additive processes, coupled with breakthroughs in new materials, which are expected to emerge over the next five to 10 years. These advanced materials will better satisfy the design requirements of many new products. The paper considers currently available technologies and discusses recent advancements in direct metal freeform fabrication and its potential of revolutionising the medical industry

Oxo and Oxofree Rhenium(V) Complexes with N,O-donor Schiff Bases

The reaction between cis-[ReVO2I(PPh3)2] and H3duo (N-(2-hydroxybenzylidene)-5-amino-1,3-dimethyl uracil) led to the formation of the oxofree, imido compound, trans-[ReV(ddd)(Hduo)(PPh3)2]I (1) (H2ddd=5,6-diamino-1,3-dimethyluracil). An oxo complex, cis-[ReV(bcp)OCl2(PPh3)](2) [Hbcp = N-(2-hydroxybenzylidene)-benzothiazole] was isolated from the reaction of trans-[ReOVCl3(PPh3)2] with Hbcp. The crystal structures of the compounds were determined by single crystal X-ray diffraction.Keywords: Rhenium(V), imido, oxo, crystal structure, spectral characterizatio

Vehicle acceleration estimation using smartphone-based sensors

Recent advances in smartphone technology, including motion sensing and wireless communications, have resulted in these devices being used for vehicle-based driver behaviour sensing applications, replacing existing bespoke vehicle-based solutions. Acceleration is normally used as the primary indicator for recklessness. Despite the many benefits of using a smartphone to determine vehicle acceleration, the mobility of the phone relative to the vehicle, and the vehicle relative to the earth, causes the earth's gravitational force to obscure the true vehicle acceleration as perceived by the phone. The design and test results in this paper demonstrate how quaternions and an unscented Kalman filter can be used to remove the gravitational vector from the sensed acceleration, which enables reckless driving detection.Paper presented at the 34th Annual Southern African Transport Conference 6-9 July 2015 "Working Together to Deliver - Sakha Sonke", CSIR International Convention Centre, Pretoria, South Africa.The Minister of Transport, South AfricaTransportation Research Board of the US

Simulating mobility to plan for electric minibus taxis in Sub-Saharan Africa's paratransit

Sub-Saharan Africa (SSA) is faced with the challenge to integrate e-mobility into its paratransit (its informal mass transit). Old, unsafe, fuel-inefficient, polluting minibus taxis are the cornerstone of daily commuting for millions in the region. Planning for electrification requires accurate high-frequency mobility data, which is currently unavailable. We analyse and improve on existing simulation models, which predict the energy usage with a micro-traffic simulation, SUMO, that up-samples low-frequency mobility data. We show that, compared to using measured mobility data, the current simulation approach overestimates energy expenditure. Results show a mean energy expenditure per distance overestimation of 14%, and mean energy per trip overestimation of 46%. We identify and virtualisation errors in the current driver and infrastructure models, and identify shortcomings of imposing a virtual road network with simulation software in the SSA context. We recommend and demonstrate virtualisation improvements for accurate electro-mobility planning in future

Factors that influence the geometric detection pattern of vehicle-based licence plate recognition camera systems

CITATION: Rademeyer, M. C., Booysen, M. J. & Barnard, A. 2018. Factors that influence the geometric detection pattern of vehicle-based licence plate recognition camera systems. In Southern African Transport Conference, 9-12 July 2018, Pretoria, South Africa.The original publication is available at http://www.satc.org.zaLicence plate recognition (LPR) systems are used to automatically extract the characters from licence plates positioned in front of a camera. The geometric detection pattern is the region within which the system can accurately recognise licence plates and is of special interest when the system is mounted in a moving vehicle. In this research, the theory surrounding camera optics was investigated and used as the basis of a software simulation model. Inspired by the simulation measurements, a real-world experimental test was conducted to further explore the influence various factors have on the geometric detection pattern. Analysis of these measurements provided greater insight how multiple factors individually contribute to the shape and size of the geometric detection pattern and serves as a guide in the design of vehicle-based LPR systems.Post-prin

Optimal use of existing freeway management surveillance infrastructure on pedestrian bridges with computer vision techniques

South Africa as a developing country has to make the most out of the infrastructure that are available. Given the high level of crash involving pedestrians, it is critical that all means available are utilised to characterise pedestrian movements on the highway and pedestrian bridges. This paper will focus on using the existing camera infrastructure, but will extend its use to automatically detect and count pedestrians that use the pedestrian bridges. The pedestrian movement data can be used to aid with the evaluation of pedestrian safety campaigns, or to recognise trends in pedestrian movement. The paper presents the impact of various parameter changes to the state of the art technique used, as well as orientation suggestions for future installations. This is done to make optimal use of existing infrastructure, and provides an alternative to existing high-end systems. The methodology includes training a computer vision-based algorithm to recognise and count pedestrians for specific scenes, for example pedestrian bridges. The paper evaluates different suppression techniques to reduce false positives. The results show that 72% of pedestrians can be detected (a hit rate of 72%), with the camera facing a pedestrian bridge squarely from the side, so that silhouettes are clearly visible. High end products not using existing infrastructure typically have a hit rate of 70%-90%. The solution in this paper competes with high-end products, and can be expanded for infrastructure security applications, e.g. monitoring copper cables or monitoring of high risk areas.Paper presented at the 35th Annual Southern African Transport Conference 4-7 July 2016 "Transport ? a catalyst for socio-economic growth and development opportunities to improve quality of life", CSIR International Convention Centre, Pretoria, South Africa.The Minister of Transport, South AfricaTransportation Research Board of the US

Client-centred design evolution via functional prototyping

The product design process involves communication of potential design solutions to customers. Fully functional prototypes are most suitable for this because they are readily accepted and allow simultaneous evaluation of all design criteria. However, they are often seen as expensive, time-consuming and not fully representative of the final product material. Therefore, they are usually reserved for customer validation of the final design rather than to keep them involved in every product evolution iteration. This research proposes that rapid prototypes should be used to facilitate a method referred to as Customer Interaction through Functional Prototypes (CIFP). An action research methodology was employed to test the efficacy of applying this method to a real-world product design brief. Customers were able to fully evaluate the aesthetic, ergonomic and functional parameters of the product during every design iteration. This resulted in accelerated product development, sensitivity to the client's needs, a new dimension of 'natural' communication and a successful product design

Saving on household electric water heating : what works best and by how much?

CITATION: Nel, P. J. C., Booysen, M. J. & Van Der Merwe, B. Saving on household electric water heating : what works best and by how much?. In IEEE Innovative Smart Grid Technologies - Asia (ISGT-Asia), 4-7 December 2017, Auckland, New Zealand, doi:10.1109/ISGT-Asia.2017.8378439.The original publication is available at https://ieeexplore.ieee.orgElectric heating of water for domestic use is a substantial component of total household energy costs. Thermal energy in a water heater is either used (as warm water) or lost to the environment. Various approaches to reduce the losses and improve the efficiency of these notoriously inefficient and costly water heaters have been proposed and are employed. However, given the complex factors at play, making sense of the savings approaches and choosing the right one for the right use case is not a simple task and often misunderstood. This paper addresses this problem by comparing some of the commonly employed approaches, including schedule control, change in set temperature, use of thermal insulation, and reduction in consumed volume. We also compare the impact of environmental factors, such as changing the ambient temperature around the water heater and the cold inlet temperature. The results show that for the consumption profiles and use cases evaluated, schedule control is the most effective, followed by insulation of the tank and piping. Combined, these two interventions save up to 25%. We also find that the effect of the temperature of the cold inlet water dwarfs that of the ambient temperature, is in line with other approaches, and means the installation status quo needs to be reconsidered.https://ieeexplore.ieee.org/document/8378439/Preprin

Using sparse categorical principal components to estimate asset indices: new methods with an application to rural southeast asia

PRIFPRI3; DCA; ISI; 4 Transforming Agricultural and Rural EconomiesDSG