3 research outputs found
Motion sickness and rigid body motion of a polar supply and research vessel on voyages to Antarctica and the Southern Ocean
Thesis (MEng)--Stellenbosch University, 2016.ENGLISH ABSTRACT: Low frequency (0.1 Hz to 0.5 Hz) lateral and vertical motion present on ocean
going vessels could cause motion sickness. ISO 2361-1 developed a means to
predict motion sickness in the vertical direction, but did not propose a means
on incorporating lateral motion. It was also hypothesised that motion on the
SA Agulhas II is expected to be either more or less provocative depending on
location. A modified six accelerometer array was developed in order to determine
the lateral and vertical acceleration levels at any location on board the SA
Agulhas II. Vertical acceleration was found vary along the width and length
of the SA Agulhas II but was independent of height. Subjective responses
of participants were collected from the personal details submission form and
daily diary. It was reported that susceptibility towards motion sickness declined
with age for the males. Females were found to be more susceptible than
males. The percentage of motion sick participants, the percentage of vomiting
participants and illness rating (N = 32) were correlated using Kendall's rank
correlation. The percentage of motion sick participants and illness rating had
the highest correlation coefficient (T) of 0.815. Participants spent most their
time in the accommodation area, centred around zone D7. Daily maximum
6 h motion sickness dose values were determined at all locations on board the
SA Agulhas II using vertical and lateral weighting filters for motion sickness.
Illness rating correlated the best with both MSDVx;6h and MSDVz;6h. Linear
and multiple non-linear regression analysis was used to determine the effects
each direction, at zone D7, has on motion sickness. Motion in y-axis was determined
to be insignificant. However multicollinearity was identified between
x- and z-axis motion, which made determining the effects of each direction impossible.
The contribution of each axis was then assumed to be the same and
a linear regression model was developed to predict illness rating (R2 = 0:417).AFRIKAANSE OPSOMMING: Lae frekwensie (0.1 Hz tot 0.5 Hz) laterale en vertikale beweging teenwoordig
see gaande vaartuie kon rysiekte veroorsaak. ISO 2361-1 ontwikkel 'n manier
om rysiekte in die vertikale rigting te voorspel, maar nie 'n manier om laterale
beweeging voor te stel en inkorporeer nie. Dit is ook veronderstel dat
beweging op die SA Agulhas II na verwagting, meer of minder uitdagend sal
wees, afhangende van die ligging. 'n Aangepaste ses verskeidenheid versnellingsmeter
is ontwikkel om die laterale en vertikale versnelling te bepaal op
enige plek aan boord op die SA Agulhas II. Daar is gevind dat die vertikale
versnelling wissel langs die breedte en lengte van die SA Agulhas II, maar was
onafhanklik van die hoogte. Subjektiewe responsie van deelnemers is ingesamel
uit die persoonlike besonderhede voorlegging vorm en daaglikse dagboek.
Dit is berig dat vatbaarheid teenoor rysiekte afneem met die ouderdom vir die
mans. Vroue is gevind meer vatbaar as mans. Die persentasie van rysiekte
deelnemers, die persentasie van braakinde deelnemers en siekte beoordeling
(N = 32), is gekorreleer met behulp van Kendall se rang korrelasie. Die persentasie
van rysiek deelnemers en siekte gradeering het die hoogste korrelasie
koëffisiënt (T) van 0.815. Deelnemers het die meeste van hul tyd in die akkommodasie
area, gesentreer rondom sone D7. Daaglikse maksimum 6 uur
rysiekte dosis waardes is bepaal op alle plekke aan boord die SA Agulhas II
met die gebruik van die vertikale en laterale gewig filters vir rysiekte. Siekte
gradeering korreleer die beste met beide MSDVx;6h en MSDVz;6h. Lineêre en
verskeie nie- lineêre regressie-analise is gebruik om die efekte te bepaal in elke
rigting, by sone D7, op rysiekte. Beweging in y-as is gering bepaal te wees.
Maar, multikollineariteit is geïdentifiseer tussen z- en z-as beweging, wat die bepaling van die gevolge van elke rigting onmoontlik maak. Die bydrae van
elke as is dan aanemende om dieselfde te wees en 'n lineêre regressiemodel is
ontwikkel om siekte gradering te voorspel (R2 = 0:417)