Process control and configuration of a reconfigurable production system using a multi-agent software system

Thesis (M. Tech. (Information Technology)) -- Central University of technology, Free State, 2011Traditional designs for component-handling platforms are rigidly linked to the product being produced. Control and monitoring methods for these platforms consist of various proprietary hardware controllers containing the control logic for the production process. Should the configuration of the component handling platform change, the controllers need to be taken offline and reprogrammed to take the changes into account. The current thinking in component-handling system design is the notion of re-configurability. Reconfigurability means that with minimum or no downtime the system can be adapted to produce another product type or overcome a device failure. The re-configurable component handling platform is built-up from groups of independent devices. These groups or cells are each responsible for some aspect of the overall production process. By moving or swopping different versions of these cells within the component-handling platform, re-configurability is achieved. Such a dynamic system requires a flexible communications platform and high-level software control architecture to accommodate the reconfigurable nature of the system. This work represents the design and testing of the core of a re-configurable production control software platform. Multiple software components work together to control and monitor a re-configurable component handling platform. The design and implementation of a production database, production ontology, communications architecture and the core multi-agent control application linking all these components together is presented

On directed interacting animals and directed percolation

We study the phase diagram of fully directed lattice animals with nearest-neighbour interactions on the square lattice. This model comprises several interesting ensembles (directed site and bond trees, bond animals, strongly embeddable animals) as special cases and its collapse transition is equivalent to a directed bond percolation threshold. Precise estimates for the animal size exponents in the different phases and for the critical fugacities of these special ensembles are obtained from a phenomenological renormalization group analysis of the correlation lengths for strips of width up to n=17. The crossover region in the vicinity of the collapse transition is analyzed in detail and the crossover exponent $\phi$ is determined directly from the singular part of the free energy. We show using scaling arguments and an exact relation due to Dhar that $\phi$ is equal to the Fisher exponent $\sigma$ governing the size distribution of large directed percolation clusters.Comment: 23 pages, 3 figures; J. Phys. A 35 (2002) 272

Joint position statement of the International Federation of Sports Medicine (FIMS) and European Federation of Sports Medicine Associations (EFSMA) on the IOC framework on fairness, inclusion and non-discrimination based on gender identity and sex variations.

The IOC recently published its framework on fairness, inclusion and non-discrimination based on gender identity and sex variations. This framework is drafted mainly from a human rights perspective, with less consideration for medical/scientific issues. The framework places the onus for gender eligibility and classification entirely on the International Federations (IFs), even though most will not have the capacity to implement the framework. The position of no presumption of advantage is contrary to the 2015 IOC consensus. Implementation of the 2021 framework will be a major challenge for IFs that have already recognised the inclusion of trans and women athletes with differences of sexual development (DSD) using a scientific/medical solution. The potential consequences for sports that need to prioritise fairness or safety could be one of two extremes (1) exclusion of all transgender or DSD athletes on the grounds of advantage or (2) self-identification that essentially equates to no eligibility rules. Exclusion of all transgender or DSD athletes is contrary to the Olympic charter and unlawful in many countries. While having no gender eligibility rules, sport loses its meaning and near-universal support. Athletes should not be under pressure to undergo medical procedures or treatment to meet eligibility criteria. However, if an athlete is fully informed and consents, then it is their free choice to undergo carefully considered or necessary interventions for gender classification for sport to compete fairly and safely in their chosen gender. Free choice is a fundamental human right, but so is the right to fair and safe competition

Ultrastructural alterations of whole blood by copper, manganese and mercury metal mixtures using a chronic in vivo model of coagulation

Globally, contamination of drinking water by heavy metals is increasing and poses a potential hazard to human health. Data on heavy metal mixtures and their effects on thrombosis are limited. The objective of this study was to determine the in vivo effects that copper, manganese and mercury, alone and in mixtures, have on clotting potential. Forty-eight male Sprague-Dawley rats were divided into eight groups, dependent on the type of heavy metal/s administered. The dosages were calculated at X100 the World Health Organisation limits in drinking water and orally administered for 28 days, at the University of Pretoria in 2018. Heavy metal induced morphological alterations of erythrocytes, platelets and fibrin networks were evaluated, using scanning electron microscopy. The manganese and mercury mixture had the greatest thrombotic potential by inducing acanthocyte and echinocyte formation, generating highly activated platelets with spontaneous fibrin formation and forming a disorganised fibrin network. In conclusion, chronic or single high dosage exposure to these heavy metals can potentially induce or contribute to thrombosis.The National Research Foundation of South Africahttp://www.elsevier.com/locate/etap2021-04-01hj2020AnatomyPhysiolog

Development of E-waste recycling infrastructure in Africa

The paper presents the activities of an alliance of original equipment manufacturers (e-waste solutions alliance for Africa). A sustainable solution to the electronic waste problem in Africa is discussed, including how the proposed solution works with the existing formal and informal sectors. The application of EPR (extended producer responsibility) is described, together with clear allocation of roles and responsibilities. The importance of clear definitions, standards and control mechanisms is presented together with key aspects and review of legislation required to facilitate business investment. In the proposed solution electronic waste management is considered an opportunity to recover valuable materials, create jobs and protect the environment and human health. The plans do not solely focus on the valuable end of life products, they also consider the entire ICT e-waste stream including problematic materials and fractions (currently being burned or landfilled), as well as materials and fractions with no value

Early time-limited antiretroviral therapy versus deferred therapy in South African infants infected with HIV: results from the children with HIV early antiretroviral (CHER) randomised trial

Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)Geneeskunde en GesondheidswetenskappePediatrie En Kindergesondhei