Modelling Pollock egg counts from the western Gulf of Alaska by a zero-inflated Bayesian hierarchical space-time model
Data from egg sampling surveys often contain a large proportion of zeros. We examine the time and location of collected walleye pollock egg counts from the western Gulf of Alaska, from Kodiak Island to Unimah Pass, in the years 1978-2000. We take the excessive number of zeros in the data into accoun...
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Matematisk Institutt, Universitetet i Oslo
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ftoslouniv:oai:www.duo.uio.no:10852/10354 2023-05-15T17:04:38+02:00 Modelling Pollock egg counts from the western Gulf of Alaska by a zero-inflated Bayesian hierarchical space-time model Tvete, Ingunn Fride Storvik, Geir Natvig, Bent 2006 http://hdl.handle.net/10852/10354 http://urn.nb.no/URN:NBN:no-28475 eng eng Matematisk Institutt, Universitetet i Oslo Preprint series. Statistical Research Report http://urn.nb.no/URN:NBN:no-23420 http://urn.nb.no/URN:NBN:no-23420 http://urn.nb.no/URN:NBN:no-28475 http://hdl.handle.net/10852/10354 URN:NBN:no-28475 132398 Fulltext https://www.duo.uio.no/bitstream/handle/10852/10354/1/stat-res-04-06.pdf © The Author(s) (2006). This material is protected by copyright law. Without explicit authorisation, reproduction is only allowed in so far as it is permitted by law or by agreement with a collecting society. Copyright 2006 The Author(s) VDP::410 Research report Forskningsrapport 2006 ftoslouniv 2021-04-28T22:31:00Z Data from egg sampling surveys often contain a large proportion of zeros. We examine the time and location of collected walleye pollock egg counts from the western Gulf of Alaska, from Kodiak Island to Unimah Pass, in the years 1978-2000. We take the excessive number of zeros in the data into account by taking a two stage modelling approach, resulting in a zero-inflated hierarchical space-time model. The binary (presence/absence of zeros) process is directly linked to the underlying intensity process. Hence, the latter process influences both the presence of zeros and the amount of eggs in non-zero observations. We fit our model for each year, and compare the underlying intensities over the years within regions of the sampled area. Report Kodiak Alaska Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Gulf of Alaska |
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Open Polar |
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Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
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language |
English |
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VDP::410 |
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VDP::410 Tvete, Ingunn Fride Storvik, Geir Natvig, Bent Modelling Pollock egg counts from the western Gulf of Alaska by a zero-inflated Bayesian hierarchical space-time model |
topic_facet |
VDP::410 |
description |
Data from egg sampling surveys often contain a large proportion of zeros. We examine the time and location of collected walleye pollock egg counts from the western Gulf of Alaska, from Kodiak Island to Unimah Pass, in the years 1978-2000. We take the excessive number of zeros in the data into account by taking a two stage modelling approach, resulting in a zero-inflated hierarchical space-time model. The binary (presence/absence of zeros) process is directly linked to the underlying intensity process. Hence, the latter process influences both the presence of zeros and the amount of eggs in non-zero observations. We fit our model for each year, and compare the underlying intensities over the years within regions of the sampled area. |
format |
Report |
author |
Tvete, Ingunn Fride Storvik, Geir Natvig, Bent |
author_facet |
Tvete, Ingunn Fride Storvik, Geir Natvig, Bent |
author_sort |
Tvete, Ingunn Fride |
title |
Modelling Pollock egg counts from the western Gulf of Alaska by a zero-inflated Bayesian hierarchical space-time model |
title_short |
Modelling Pollock egg counts from the western Gulf of Alaska by a zero-inflated Bayesian hierarchical space-time model |
title_full |
Modelling Pollock egg counts from the western Gulf of Alaska by a zero-inflated Bayesian hierarchical space-time model |
title_fullStr |
Modelling Pollock egg counts from the western Gulf of Alaska by a zero-inflated Bayesian hierarchical space-time model |
title_full_unstemmed |
Modelling Pollock egg counts from the western Gulf of Alaska by a zero-inflated Bayesian hierarchical space-time model |
title_sort |
modelling pollock egg counts from the western gulf of alaska by a zero-inflated bayesian hierarchical space-time model |
publisher |
Matematisk Institutt, Universitetet i Oslo |
publishDate |
2006 |
url |
http://hdl.handle.net/10852/10354 http://urn.nb.no/URN:NBN:no-28475 |
geographic |
Gulf of Alaska |
geographic_facet |
Gulf of Alaska |
genre |
Kodiak Alaska |
genre_facet |
Kodiak Alaska |
op_relation |
Preprint series. Statistical Research Report http://urn.nb.no/URN:NBN:no-23420 http://urn.nb.no/URN:NBN:no-23420 http://urn.nb.no/URN:NBN:no-28475 http://hdl.handle.net/10852/10354 URN:NBN:no-28475 132398 Fulltext https://www.duo.uio.no/bitstream/handle/10852/10354/1/stat-res-04-06.pdf |
op_rights |
© The Author(s) (2006). This material is protected by copyright law. Without explicit authorisation, reproduction is only allowed in so far as it is permitted by law or by agreement with a collecting society. Copyright 2006 The Author(s) |
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1766058948822040576 |