South African Tuberculosis Vaccine Initiative
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Automatically Generating IsiZulu Words From Indo-Arabic Numerals
No full textArtificial conversational agents are deployed to assist humans in a variety of tasks. Some of these tasks require the capability to communicate numbers as part of their internal and abstract representations of meaning, such as for banking and scheduling appointments. They currently cannot do so for isiZulu because there are no algorithms to do so due to a lack of speech and text data and the transformation is complex and it may include dependence on the type of noun that is counted.
We solved this by extracting and iteratively improving on the rules for speaking and writing numerals as words and creating two algorithms to automate the transformation. Evaluation of the algorithms by two isiZulu grammarians showed that six out of seven number categories were 90-100\% correct. The same software was used with an additional set of rules to create a large monolingual text corpus, made up of 771 643 sentences, to enable future data-driven approaches
Volcanic Skies: coupling explosive eruptions with atmospheric simulation to create consistent skyscapes
Full text linkExplosive volcanic eruptions rank among the most terrifying natural phenomena, and are thus frequently depicted in films, games, and other media, usually with a bespoke once-off solution. In this paper, we introduce the first general-purpose model for bi-directional interaction between the atmosphere and a volcano plume. In line with recent interactive volcano models, we approximate the plume dynamics with Lagrangian disks and spheres and the atmosphere with sparse layers of 2D Eulerian grids, enabling us to focus on the transfer of physical quantities such as temperature, ash, moisture, and wind velocity between these sub-models. We subsequently generate volumetric animations by noise-based procedural upsampling keyed to aspects of advection, convection, moisture, and ash content to generate a fully-realized volcanic skyscape. Our model captures most of the visually salient features emerging from volcano-sky interaction, such as windswept plumes, enmeshed cap, bell and skirt clouds, shockwave effects, ash rain, and sheathes of lightning visible in the dark
Collective Infrastructural Speculations: A Situated Understanding of Pasts, Presents & Futures of Resilient Community Networks.
Full text linkCommunity Networks (CNs) offer a means for high-quality communication infrastructure growth, especially in rural areas providing benefits to social and economic development; CNs hold potential to be community-owned infrastructure fostering community resilience. Towards realizing this potential of CNs, we explored two research questions: What does resilience mean for the communities who build, maintain, and use a CN; and what are community-based visions for fostering resilience and sustainability of their CNs? We carried out four speculative design workshops with different stakeholders at two CNs: Ocean View Community's CN in South Africa and the Channapatna Health Library's CN in India. We report our findings as two design fictions that emerged as collaborative articulation of our collective visions, acting as ‘Infrastructural Speculations’ nuancing our understanding of resilience in CNs. We offer insights into how speculative design could become a part of ongoing, situated participatory design and infrastructuring work
A UAV-based sparse viewpoint planning framework for detailed 3D modelling of cultural heritage monuments
No full textCreating 3D digital models of heritage sites typically involves laser scanning and photogrammetry. Although laser scan-derived point clouds provide detailed geometry, occlusions and hidden areas often lead to gaps. Terrestrial and UAV photography can largely fill these gaps and also enhance definition and accuracy at edges and corners. Historical buildings with complex architectural or decorative details require a systematically planned combination of laser scanning with handheld and UAV photography. High-resolution photography not only enhances the geometry of 3D building models but also improves their texturing. The use of cameras, especially UAV cameras, requires robust viewpoint planning to ensure sufficient coverage of the documented structure whilst minimising viewpoints for efficient image acquisition and processing economy. Determining
ideal viewpoints for detailed modelling is challenging. Existing planners, relying on coarse scene proxies, often miss fine structures, significantly restrict the search space of candidate viewpoints and surface targets due to high computational costs, and are sensitive to surface orientation errors, which limits their applicability
in complex scenarios. To address these limitations, we propose a strategy for generating sparse viewpoints from point clouds for efficient and accurate UAV-based modelling. Unlike existing planners, our backward visibility approach enables exploration of the camera viewpoint space at low computational cost and does not require surface orientation (normal vector) estimation. We introduce an observability-based planning criterion,
a direction diversity-driven reconstructability criterion, which assesses modelling quality by encouraging global diversity in viewing directions, and a coarse-to-fine adaptive viewpoint search approach that builds on these criteria. The approach was validated on a number of complex heritage scenes. It achieves efficient modelling
with minimal viewpoints and accurately captures fine structures, like thin spires, that are problematic for other planners. For our test examples, we achieve at least 98% coverage, using significantly fewer viewpoints, and with a consistently high structural similarity across all models
Morpho-Material Evolution for Automated Robot Design
Full text linkMulti-Level Evolution (MLE) has been demonstrated for effective
robot designs using a bottom-up approach, first evolving which
materials to use for modular components and then how these
components are connected into a functional robot design. This
paper evaluates hierarchical MLE robotic design, as an evolutionary
design method on various task (robot ambulation) environments
in comparison to human designed robots (pre-designed robot
controller-morphology couplings). Results indicate that the MLE
method evolves robots that are effective across increasingly difficult
(locomotion) task environments, out-performing pre-designed
robots, and thus provide further support for the efficacy of MLE
as an evolutionary robotic design method. Furthermore, results
indicate the MLE method enables the evolution of suitable robotic
designs for various environments, where such designs would be
non-intuitive and unlikely in conventional robotic design
Ontology Pattern Substitution: Toward their use for domain ontologies.
No full textAs ontologies find an ever-larger number of applications, the diversity of domain ontologies and the requirements for their intended uses increases as well, creating challenges for interoperability and tooling. There are often multiple ways of modelling the same knowledge, which have coalesced into ontology patterns and modelling styles, and pattern alignments for perceived to semantically the same domain knowledge have been identified. To facilitate interoperability and applicability of foundational ontology-based modelling choices with domain ontologies and so-called application ontologies or conceptual data models, we propose a general framework for the substitution of one pattern for another. This can be applied by various methods, including purely syntactic comparisons. A proof-of-concept tool that implements such a syntax-based approach for FOL ontologies encoded in CLIF is demonstrated and evaluated against a set of DOLCE-aligned ontologies
Automating Robot Design with Multi-Level Evolution
Full text linkIn evolutionary robotics, Multi-Level Evolution
(MLE) has been demonstrated for effective robot designs using
a bottom-up approach, first evolving which materials to use
for modular components and then how these components are
connected into a functional robot design. This paper evaluates
MLE robotic design, as an evolutionary design method on various
task (robot ambulation) environments in comparison to human
designed robots (pre-designed robot controller-morphology couplings).
Results indicate that the MLE method evolves robots
that are effective across increasingly difficult (locomotion) task
environments, out-performing pre-designed robots, and thus provide
further support for the efficacy of MLE as an evolutionary
robotic design method. Furthermore, results indicate the MLE
method enables the evolution of suitable robotic designs for
various environments, where such designs would be non-intuitive
and unlikely in conventional robotic design
Companion Proceedings of the 42nd International Conference on Conceptual Modeling: ER Forum, 7th SCME, Project Exhibitions, Posters and Demos, and Doctoral Consortium (ER-Companion 2023)
No full textMultipath parsing in the brain
Full text linkHumans understand sentences word-by-word, in the order that they hear them. This incrementality entails resolving temporary ambiguities about syntactic relationships. We investigate how humans process these syntactic ambiguities by correlating predictions from incremental generative dependency parsers with timecourse data from people undergoing functional neuroimaging while listening to an audiobook. In particular, we compare competing hypotheses regarding the number of developing syntactic analyses in play during word-by-word comprehension: one vs more than one. This comparison involves evaluating syntactic surprisal from a state-of-the-art dependency parser with LLM-adapted encodings against an existing fMRI dataset. In both English and Chinese data, we find evidence for multipath parsing. Brain regions associated with this multipath effect include bilateral superior temporal gyrus
User-centred design and development of a web-based Western Cape substance use assessment tool(WC-SUDAT)
Full text linkSubstance use disorders (SUDs), the uncontrolled use of substances despite harmful consequences, is a significant problem in South Africa, especially in the Western Cape. An important component in the fight against SUDs are questionnaires to assess the risk of an SUD, that are administered by social workers to identify targeted interventions. A web-based questionnaire with automated aggregation of responses can reduce the administrative burden placed on social workers. Here we use a user-centred design approach to build a web-based substance use disorder assessment tool localised to the Western Cape: WC-SUDAT. Our three-phase User Centred Design methodology comprised a first prototype; followed by evaluation of its suitability through a contextual inquiry, a usability test and heuristic evaluation; and then implementation of a final prototype incorporating unanticipated features critical
for field use that were identified in the evaluation. This process was effective in generating a final prototype webtool with a dual function as both an SUD assessment tool and an organisational management tool. This deployment-ready prototype is a better fit for the needs of NGOs working with substance abuse disorders than our original conception of the webtool, thus validating a User-Centred design approach