Motion sickness and rigid body motion of a polar supply and research vessel on voyages to Antarctica and the Southern Ocean

Boulle, Brendan Guy (2016-03)

Thesis (MEng)--Stellenbosch University, 2016.

Thesis

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).

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/98573
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