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26 M.S. MERDİVENCİ, A.G. AVCI, B. BARLAS

Those related to inducement, ie. motion type and provocative property of inducement,
Those related to the persons themself, ie. orientation, sensitization, hypersensitivity or
individual differences.

The last years innovation of transport and industry have extended the range of provocative
motion environments, to cars, tilting trains, aircrafts and high speed boats. This general term
“motion sickness” is best applied across all of those stimulus specific terms such as travel
sickness, car sickness, air sickness or sea sickness.

2.2 Analyzing Accelerations

To measure the dynamics of a moving craft, it is the best option the measurement device at a
position where we expect the least (smallest) transients accelerations. This is typically close to
the centre of gravity (CG) of the craft since any rotations around the centre of gravity into
centripetal accelerations at any point of rotation, which is usually close to the CG. There are
some existing standards that might help boat designers and builders determine limits for “how
much” and “what kind of exposure” is safe or dangerous.

Some of the existing standards are,

European Union Directive 2002/44/EC,
ISO 2631-1 [23],
ISO 2631-5 [24],
Annex 10 of 2000 HSC CODE,
Root mean square (RMS) value,
The acceleration dose,
Vibration dose value(VDV),
Crest Factor,
Impact Count Index(ICI),
Sed 8,
Peak Over Threshold(POT)

2.3 Vibration Dose Values

Vibration Dose Values (VDV) were determined for each axis the VDV was calculated by

(1)

where T is the duration of the exposure and a is the frequency weighted acceleration.

The unit of measure of VDV is ms-1.75. The weightings used were Wd for the X and Y axes, and
Wb for the Z axis. The combined VDV in all axes was determined by

(2)

and the total VDV of both trials by,

GiDB|DERGi Sayı 3, 2015