An Augmented Interaction Strategy For Designing Human-Machine Interfaces For Hydraulic Excavators

Lack of adequate information feedback and work visibility, and fatigue due to repetition have been identified as the major usability gaps in the human-machine interface (HMI) design of modern hydraulic excavators that subject operators to undue mental and physical workload, resulting in poor performance. To address these gaps, this work proposed an innovative interaction strategy, termed “augmented interaction”, for enhancing the usability of the hydraulic excavator. Augmented interaction involves the embodiment of heads-up display and coordinated control schemes into an efficient, effective and safe HMI. Augmented interaction was demonstrated using a framework consisting of three phases: Design, Implementation/Visualization, and Evaluation (D.IV.E). Guided by this framework, two alternative HMI design concepts (Design A: featuring heads-up display and coordinated control; and Design B: featuring heads-up display and joystick controls) in addition to the existing HMI design (Design C: featuring monitor display and joystick controls) were prototyped. A mixed reality seating buck simulator, named the Hydraulic Excavator Augmented Reality Simulator (H.E.A.R.S), was used to implement the designs and simulate a work environment along with a rock excavation task scenario. A usability evaluation was conducted with twenty participants to characterize the impact of the new HMI types using quantitative (task completion time, TCT; and operating error, OER) and qualitative (subjective workload and user preference) metrics. The results indicated that participants had a shorter TCT with Design A. For OER, there was a lower error probability due to collisions (PER1) with Design A, and lower error probability due to misses (PER2)with Design B. The subjective measures showed a lower overall workload and a high preference for Design B. It was concluded that augmented interaction provides a viable solution for enhancing the usability of the HMI of a hydraulic excavator

The Efficiency of Secondary Education in Sub-Saharan Africa: EESSA Project The Case of Malawi

There is limited research on secondary education in sub-Saharan Africa that explores the key factors which can promote efficient and effective secondary schools. What there is includes IIEP studies by Lewin and Caillods (2001), and the outputs from the World Bank's Secondary Education in Africa programme that includes analysis of costs and efficiency (Lewin 2008). Knowledge gaps remain with the risk that African governments embarking on large scale reforms in secondary education may invest in ways that fail to identify the components of the system and processes that drive efficient and effective delivery of secondary education, and therefore which areas to prioritize investment to achieve universal access. This study of secondary school efficiency and effectiveness in Malawi responds to this gap and provides evidence to inform discussions about key reforms in secondary education to improve quality and equitable access, especially for disadvantaged groups.Using both survey and case study data, the study analysed school efficiency in different types and sizes of secondary schools. The main output measure was final examination grades. For an estimation of inputs, teacher numbers, student-teacher ratio, class sizes, teacher quality (qualified/unqualified), and other infrastructure and material resources in schools was used. The samples sizes for the analysis was based on 88 secondary schools

Social factors influencing child health in Ghana

Objectives Social factors have profound effects on health. Children are especially vulnerable to social influences, particularly in their early years. Adverse social exposures in childhood can lead to chronic disorders later in life. Here, we sought to identify and evaluate the impact of social factors on child health in Ghana. As Ghana is unlikely to achieve the Millennium Development Goals’ target of reducing child mortality by two-thirds between 1990 and 2015, we deemed it necessary to identify social determinants that might have contributed to the non-realisation of this goal. Methods ScienceDirect, PubMed, MEDLINE via EBSCO and Google Scholar were searched for published articles reporting on the influence of social factors on child health in Ghana. After screening the 98 articles identified, 34 of them that met our inclusion criteria were selected for qualitative review. Results Major social factors influencing child health in the country include maternal education, rural-urban disparities (place of residence), family income (wealth/poverty) and high dependency (multiparousity). These factors are associated with child mortality, nutritional status of children, completion of immunisation programmes, health-seeking behaviour and hygiene practices. Conclusions Several social factors influence child health outcomes in Ghana. Developing more effective responses to these social determinants would require sustainable efforts from all stakeholders including the Government, healthcare providers and families. We recommend the development of interventions that would support families through direct social support initiatives aimed at alleviating poverty and inequality, and indirect approaches targeted at eliminating the dependence of poor health outcomes on social factors. Importantly, the expansion of quality free education interventions to improve would-be-mother’s health knowledge is emphasised

A vision of successful schooling: Ghanaian teachers' understanding of learning, teaching and assessment

This article reports on an empirical study exploring Ghanaian teachers understandings of teaching, learning and assessment. It argues that received views of poorly trained teachers with untheorized and badly reasoned professional practices may mask a more complex situation. In defining learning, teachers in the study reproduced models consistent with transmission or behaviouristic theories. However, when asked to describe their most successful experiences, teachers understandings were more in accord with social constructivism. Also, their aspiration towards interactive models of classroom assessment was circumscribed by the normal context of assessment discourse and by bureaucratic requirements. The paper concludes that, given the right circumstances, teachers can reflect on their experiences and produce a more sophisticated account of teaching and learning. It suggests ways in which in-service work might be make use of these insights, recommending further attention to the discursive frames of teachers professional reflections within dialogue and active engagement through school-based coaching

Efficiency and effectiveness of secondary education in sub-Saharan Africa, EESSA project. The case of Uganda and Malawi. [Quantitative report]

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