Use of MMG signals for the control of powered orthotic devices: Development of a rectus femoris measurement protocol

Copyright © 2009 Rehabilitation Engineering and Assistive Technology Society (RESNA). This is an Author's Accepted Manuscript of an article published in Assistive Technology, 21(1), 1 - 12, 2009, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/10400430902945678.A test protocol is defined for the purpose of measuring rectus femoris mechanomyographic (MMG) signals. The protocol is specified in terms of the following: measurement equipment, signal processing requirements, human postural requirements, test rig, sensor placement, sensor dermal fixation, and test procedure. Preliminary tests of the statistical nature of rectus femoris MMG signals were performed, and Gaussianity was evaluated by means of a two-sided Kolmogorov-Smirnov test. For all 100 MMG data sets obtained from the testing of two volunteers, the null hypothesis of Gaussianity was rejected at the 1%, 5%, and 10% significance levels. Most skewness values were found to be greater than 0.0, while all kurtosis values were found to be greater than 3.0. A statistical convergence analysis also performed on the same 100 MMG data sets suggested that 25 MMG acquisitions should prove sufficient to statistically characterize rectus femoris MMG. This conclusion is supported by the qualitative characteristics of the mean rectus femoris MMG power spectral densities obtained using 25 averages

Challenges and opportunities in the design and construction of a GIS-based emission inventory infrastructure for the Niger Delta region of Nigeria

© 2017, Springer-Verlag Berlin Heidelberg. Environmental monitoring in middle- and low-income countries is hampered by many factors which include enactment and enforcement of legislations; deficiencies in environmental data reporting and documentation; inconsistent, incomplete and unverifiable data; a lack of access to data; and technical expertise. This paper describes the processes undertaken and the major challenges encountered in the construction of the first Niger Delta Emission Inventory (NDEI) for criteria air pollutants and CO2 released from the anthropogenic activities in the region. This study focused on using publicly available government and research data. The NDEI has been designed to provide a Geographic Information System-based component of an air quality and carbon management framework. The NDEI infrastructure was designed and constructed at 1-, 10- and 20-km grid resolutions for point, line and area sources using industry standard processes and emission factors derived from activities similar to those in the Niger Delta. Due to inadequate, incomplete, potentially inaccurate and unavailable data, the infrastructure was populated with data based on a series of best possible assumptions for key emission sources. This produces outputs with variable levels of certainty, which also highlights the critical challenges in the estimation of emissions from a developing country. However, the infrastructure is functional and has the ability to produce spatially resolved emission estimates

Economic-environmental trade-offs and the conservativeness of the upper partial moment

Probabilistic programming are typically used to model economic-environmental trade-when environmental outcomes are stochastic. Application of available probabilistic programming techniques such as the upper partial moment (UPM) is problematic due to the conservativeness of the estimated the compliance probability. Conservatively estimated trade-offs may result in overregulation of agricultural production practices. Although the conservativeness of the UPM is usually acknowledged by researchers, none of the researchers investigated the size of conservativeness of the UPM. An alternative non-linear trade-off model specification is developed to investigate the conservativeness of the UPM. Meta data from the validated Soil Water Balance (SWB) crop growth simulation model for irrigated maize in South Africa is used to show that the UPM is very conservative in the estimation of the trade-offs comparing to the new method. However, the size of the conservativeness is very situation-specific and varies due to differences in fixed resources, fertilizer application methods and conservativeness measures