26 research outputs found
EMERGING TECHNOLOGIES: COMMERCIAL READINESS INDEX (CRI) FOR MEDICAL ADDITIVE MANUFACTURING (AM)
ArticleTechnology Readiness Level (TRL) is widely used as a measure of technology maturity. However, TRL is not necessarily a good indicator of commercial readiness. In the renewable energy sector a Commercial Readiness Index (CRI) is used where only a technology with a high TRL qualifies for commercial readiness. Similarly TRL is used to measure the maturity of Additive Manufacturing (AM) technologies. This research proposes a Commercial Readiness Index (CRI) for Additive Manufacturing. A case-study on maxillofacial Ti6Al4V implants manufactured with AM is referred to
Review and analysis of work sampling methods : the case of an automated labour performance measurement system using the work sampling method
Published ArticleThis paper analyses work sampling and time study as work measurement methods with the view of employing them in an automated labour performance measurement system. These are compared with respect to Hawthorn effect, labour intensiveness, cost, tediousness and knowledge extensiveness. The analysis proves that work sampling is a better option for developing an automated labour performance measurement system that employs computer vision. Web cameras are used to feed real-time images to a central computer via USB extenders. The computer runs a standalone C++ application that uses a random function to establish when measurements are to be taken. The developed video camera footage is converted into a pixel matrix using OpenCV. This matrix is then filtered and analysed, enabling the tracking of a worker. The data generated is stored in text files. After the work sampling period has elapsed, the data is transferred into Microsoft Excel for analysis. Finally a report of the labour utilisation is generated in Microsoft Excel and then send to the analyst for review
Evaluating the relationship between external markers and internal vertebral kinematics in the cervical spine
Published ArticleThe objective of this study was to examine the relationship between external markers typically used in external motion capturing devices and the true vertebral kinematics in the cervical spine. Twenty one healthy subjects were subjected to low dosage X-rays in five different positions, while radio opaque markers were attached to the skin at each vertebral level. Distance and angle parameters were constructed for vertebral prediction from skin surface markers. The causes of variation in these parameters were identified by investigating the correlations of these parameters with anthropometrical variables. Strong correlations of the parameters were observed in flexion, but in extension, especially full extension, the correlations were poor to insignificant. In neutral, half flexion, and full flexion it is possible to predict the vertebral position from surface markers by using the parameters and anthropometrical variables. In half extension this prediction is less accurate and in full extension alternative methods should be investigated for external motion capturing
Application of an automated labour performance measuring system at a confectionery company
Published ArticleThis paper focuses on the implementation of a labour performance measuring system at a confectionery company. The computer vision based system is based on the work sampling methodology. It consists of four cameras linked to a central computer via USB extenders. The computer uses a random function in C++ in order to determine when measurements are to be taken. OpenCV is used to track the movement of a target worker's dominant hand at a given work station. Tracking is accomplished through the use of a bandwidth colour filter. The speed of the worker's hand is used to identify whether the worker is busy, idle or out of the frame over the course of the sampling period. Data collected by the system is written into a number of text files. The stored data is then exported to a Microsoft Excel 2007 spread sheet where it is analysed and a report on the labour utilisation is generated
Investigation of the effects of lubricant fat content on drawn copper wires
The Lean Manufacturing goal of reducing waste and increasing productivity has made it a necessity to produce good quality products in manufacturing industries at a low cost. In the cable manufacturing companies this can be achieved by optimising the wire drawing process. One way to meet the desired quality of the drawn wires is to improve lubricant efficiency through installation of an automatic, continuous lubricant fat content control system on the drawing machine. The paper shows a method of finding the optimum lubricant concentration for producing good quality copper wires using Taguchi experiments. Taguchi experiments are employed to analyse the effects of different lubricant fat content levels on the tensile strength and lubricant temperature. The results from the experiments indicated that the tensile strength of the wire is affected by low lubricant fat content. The lower the lubricant fat content: the lower the tensile strength drawing lubricant resulting in numerous wire breakages that affect the quality of the final product, namely the cable
Design of an automated grinding media charging system for ball mills
The parameters of mill load (ML) not only represent the load of the ball mill, but also determine the grinding production ratio (GPR) of the grinding process. Monitoring and recognition of milling conditions have significant effect on the operating efficiency, product quality, and energy and grinding media consumption for the milling circuit. This paper presents an automated grinding media charging system incorporating a multi-agent system developed in Java Agent Development Environment (JADE). A control logix program is designed to determine the precise quantities of grinding media to be charged in an incremental manner such that shock loading is avoided. The multi-agent system created in JADE monitors the power drawn and the mill load of the ball mill such that proper charging conditions are established. High quality of the regulation process is achieved through utilization of the control logix and the multi-agent system
Development of a resource agent for an e-manufacturing system
Due to globalisation and distributed manufacturing systems the development and manufacture of products is no longer an isolated activity undertaken by either one discipline or a single organization but has become a global process. Using e-manufacturing companies can now outsource to manufacturers outside their geographical area and make them dependent on the production capabilities and responsiveness of the suppliers. Hence there is need for the suppliers to provide reliable information on the state of the orders being processed. E-manufacturing promises companies to exchange the required information with their suppliers by increased visibility to the shop floor and providing a platform for information interchange. The paper discusses the development of an e-manufacturing resource agent to enable manufactures to predict the probability of their outsourced machinery being available and the probability to complete an order without having a breakdown. The Maintenance Free Operation Period (MFOP) method is used to develop the agent. This means that the manufacturer will be expected to have a guarantee that no unscheduled maintenance activities will occur during each defined period of operation with the predefined level of confidence
Changes in phosphorus status of 'Cripps' Pink' apple trees after application of mulches
The effect of four different mulches on fruit quality was quantified, either
directly via mineral nutrient contributions or indirectly, by increasing nutrient uptake
efficiency in the soil. We hypothesised that fruit nutrient levels would increase more
when an organic mulch, containing nutrients, was applied to the soil, with smaller/no
increases when an inorganic mulch was applied to the tree row.
In this paper, we concentrate on changes in fruit phosphorus (P) concentrations
after application of five treatments: a clean cultivated control, an inorganic woven
geotextile fabric, and organic mulches – compost, wood chips and a vermi-castings/
wood chips combination. The trial was conducted on a commercial farm, Lourensford
Estate, South Africa, from October 2008 to April 2012 – on an adjacent light, sandy and
heavier, sandy-silt soil.
Mineral nutrient analyses of the soil, leaves, mulches and fruit were performed.
Yield and fruit size were determined. Soil temperatures and soil water status were
recorded hourly during the last two seasons. P concentrations did increase chronologically
from the soil, then into leaves and then into the fruit after application of
mulches that provided additional P to the soil. Sporadic increases in both leaves and
fruit occurred, but could not always be related to treatment effects. The significant
consistent increase of P levels of the vermi-castings treatment in the heavy soil is likely
to be a combination of reduced irrigation volumes, as well as a treatment effect.
All mulches resulted in the well-established buffering of soil temperatures, soil water content and percentage soil carbon. Based on results from this study, it is not
feasible to apply mulches for the sole purpose to increase P levels in the soil, leaves or
fruit of established trees – although increases were noticed from time to time. In
addition to water and temperature modifying effects of mulches that would differ
between soil textures and depend on the mulch source, increases in P concentrations
may result. As yield efficiency is still the primary factor determining income per hectare
for the producer, the decrease in yield that resulted from mulching under these
conditions, will still outweigh any positive contributions of mulches. It is therefore of
utmost importance to first adjust irrigation volumes to a mulch treatment before the
advantageous properties of mulching will be of value.Stellenbosch University and
HortgroScience.http://www.actahort.orgam201
The MeerKAT Galaxy Cluster Legacy Survey: I. Survey overview and highlights
Please abstract in the article.The South African Radio Astronomy Observatory (SARAO), the National Research Foundation (NRF), the National Radio Astronomy Observatory, US National Science Foundation, the South African Research Chairs Initiative of the DSI/NRF, the SARAO HCD programme, the South African Research Chairs Initiative of the Department of Science and Innovation.http://www.aanda.orghj2022Physic