Detection of static and dynamic activities using uniaxial accelerometers

Rehabilitation treatment may be improved by objective analysis of activities of daily living. For this reason, the feasibility of distinguishing several static and dynamic activities (standing, sitting, lying, walking, ascending stairs, descending stairs, cycling) using a small set of two or three uniaxial accelerometers mounted on the body was investigated. The accelerometer signals can be measured with a portable data acquisition system, which potentially makes it possible to perform online detection of static and dynamic activities in the home environment. However, the procedures described in this paper have yet to be evaluated in the home environment. Experiments were conducted on ten healthy subjects, with accelerometers mounted on several positions and orientations on the body, performing static and dynamic activities according to a fixed protocol. Specifically, accelerometers on the sternum and thigh were evaluated. These accelerometers were oriented in the sagittal plane, perpendicular to the long axis of the segment (tangential), or along this axis (radial). First, discrimination between the static or dynamic character of activities was investigated. This appeared to be feasible using an rms-detector applied on the signal of one sensor tangentially mounted on the thigh. Second, the distinction between static activities was investigated. Standing, sitting, lying supine, on a side and prone could be distinguished by observing the static signals of two accelerometers, one mounted tangentially on the thigh, and the second mounted radially on the sternum. Third, the distinction between the cyclical dynamic activities walking, stair ascent, stair descent and cycling was investigated. The discriminating potentials of several features of the accelerometer signals were assessed: the mean value, the standard deviation, the cycle time and the morphology. Signal morphology was expressed by the maximal cross-correlation coefficients with template signals for the different dynamic activities. The mean signal values and signal morphology of accelerometers mounted tangentially on the thigh and the sternum appeared to contribute to the discrimination of dynamic activities with varying detection performances. The standard deviation of the signal and the cycle time were primarily related to the speed of the dynamic activities, and did not contribute to the discrimination of the activities. Therefore, discrimination of dynamic activities on the basis of the combined evaluation of the mean signal value and signal morphology is propose

Don’t Shoot the Messenger–Reflections on streamlining and simplification of Environmental Assessment in the Netherlands

The Netherlands’ Environmental Assessment (EA) system has continuously been discussed with calls for streamlining and simplifying. This paper aims to provide an overview and to examine these discussions, including their more fundamental background. To this end, we discuss the origins of the Dutch EA-system, its practice, the critique, the regulator’s reaction by changing institutional arrangements, and the consequences. We conclude that politically, EA is blamed for cumbersome planning and decision-making, while professionals are more nuanced. We see a process of persistent cumbersome planning and decision-making about plans and projects in a country in which environment and nature are under pressure. This situation is resulting in impromptu ‘escape routes’ and evermore detailed EA-studies that are costly, time-consuming, lack quality, are contested, and often fail before court. This process is observed for a long time. Although most studies stressed that streamlining and simplifying will not help in accelerating the planning process, nevertheless regulatory changes aimed at this because of political pressure. Overall, as a consequence of the simplification of regulations and the reduction of safeguards, the advanced and comprehensive nature of the original Dutch EIA-system has been called into question. EA as a messenger intrinsically will always be subject to critique.</p

Language Selection Policies in International Standardization – Perception of the IEC Member Countries

International standards setting organizations have different language selection policies. These policies have, besides their financial aspects, also an important cultural/ political dimension. The standards setting organizations are either bilingual (English/ French), or unilingual (English), or multilingual (English, French and further languages). We have investigated the references of the 65 national members of the International Electrotechnical Commission (IEC). The main findings are a moderate preference for the use of both English and French for the technical work, and a strong preference for the use of English only for communication.. The obvious dominance of the English language is seen as a necessity, rather than an indication of a hypothetical Anglo-American linguistic/ cultural imperialism. Finally, some conclusions regarding language selection policies in international standards setting organizations are presented

Effectieve verenigingsondersteuning in de provincie Groningen

Onderzoek naar de effectiviteit van verenigingsondersteuning in de provincie Groningen in opdracht van Sportplein Groningen en de provincie. Op basis van focus groepen en interviews is er gekeken in welke mate verenigingsondersteuners de ruimte krijgen en nemen om zichzelf te ontwikkelen, kennis uit te wisselen en inzicht hebben in de effecten van hun interventies bij sportverenigingen

Maatschappelijke spin-off van side-events WK CP Voetbal 2011

Onderzoek naar de effectiviteit van het side-event programma bij het wereldkampioenschoep CP Voetbal in Drenthe in 2011. Onderzocht is in welke mate de verschillende side-events een bijdrage leverden aan de doelstellingen van het hoofdevenement. Het onderzoek vond plaats binnen het kader van de pilot van het Ministerie van Volksgezondheid, Welzijn en Sport (VWS) om kennis te ontwikkelen over sportevenementen

IMPACT STRENGTH OF 3D-PRINTED POLYCARBONATE

A vertical wall printed by Fused Filament Fabrication consists of a ribbed surface profile, due to the layer wise deposition of molten plastic. The notches between the printed layers act as stress concentrators and decrease its resistance to impact. This article shows the relation between impact strength and layer height by experimental data and finite element simulations of the stress intensity factor and the plastic zone near the tip of the notch. The impact resistance increased from 6 to 32 kJ/m2, when the layer height was decreased from 1.8 to 0.2 mm. When notches were removed by sanding, the samples did not fail any more during impact testing, resembling the behavior of smooth molded test bars. Tensile strength values up to 61 MPa were measured independent of layer height. Birefringence measurements were done to determine the actual stress levels, which ranged from 2 to 5 MPa

LIFETIME ASPECTS OF WEARABLE ELECTRONICS

In the course of two European projects the endurance behavior of stretchable electronic substrates and of electronic textiles was investigated. The results have to a large extent been published already. In this work new analyses to the earlier results are presented. Straightforward analytical approaches are used to describe fatigue under cyclic mechanical loading in the two technologies. For stretchable substrates the actual plastic strain upon stretching could be qualitatively evaluated to replace the engineering strain. For the textile-based substrates the bending strain was estimated. Additionally, there are sub-categories within each technology which perform differently and apparently show percolation behavior