Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Joint spatial modeling of significant wave height and wave period using
  the SPDE approach   The ocean wave distribution in a specific region of space and time is
described by its sea state. Knowledge about the sea states a ship encounters on
a journey can be used to assess various parameters of risk and wear associated
with the journey.
  Two important characteristics of the sea state are the significant wave
height and mean wave period. We propose a joint spatial model of these two
quantities on the north Atlantic ocean. The model describes the distribution of
the logarithm of the two quantities as a bivariate Gaussian random field. This
random field is modeled as a solution to a system of coupled stochastic partial
differential equations. The bivariate random field can model a wide variety of
non-stationary anisotropy and allows for arbitrary, and different,
differentiability for the two marginal fields.
  The parameters of the model are estimated on data of the north Atlantic using
a stepwise maximum likelihood method. The fitted model is used to derive the
distribution of accumulated fatigue damage for a ship sailing a transatlantic
route. Also, a method for estimating the risk of capsizing due to broaching-to,
based on the joint distribution of the two sea state characteristics, is
investigated. The risks are calculated for a transatlantic route between
America and Europe using both data and the fitted model.
  The results show that the model compares well with observed data. Also, it
shows that the bivariate model is needed and cannot simply be approximated by a
model of significant wave height alone.

31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th