his.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
SpecNet: A Spatial Network Algorithm that Generates a Wide Range of Specific Structures
University of Skövde, The Systems Biology Research Centre. University of Skövde, School of Life Sciences.
University of Skövde, The Systems Biology Research Centre. University of Skövde, School of Life Sciences. Department of Physics and Measurement Technology, Biology and Chemistry, Theory and Modelling, Linköping University, Linköping, Sweden.
Department of Physics and Measurement Technology, Biology and Chemistry, Theory and Modelling, Linköping University, Linköping, Sweden.
University of Skövde, The Systems Biology Research Centre. University of Skövde, School of Life Sciences.ORCID iD: 0000-0002-3965-7371
2012 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 8, e42679Article in journal (Refereed) Published
Abstract [en]

Network measures are used to predict the behavior of different systems. To be able to investigate how various structures behave and interact we need a wide range of theoretical networks to explore. Both spatial and non-spatial methods exist for generating networks but they are limited in the ability of producing wide range of network structures. We extend an earlier version of a spatial spectral network algorithm to generate a large variety of networks across almost all the theoretical spectra of the following network measures: average clustering coefficient, degree assortativity, fragmentation index, and mean degree. We compare this extended spatial spectral network-generating algorithm with a non-spatial algorithm regarding their ability to create networks with different structures and network measures. The spatial spectral networkgenerating algorithm can generate networks over a much broader scale than the non-spatial and other known network algorithms. To exemplify the ability to regenerate real networks, we regenerate networks with structures similar to two real Swedish swine transport networks. Results show that the spatial algorithm is an appropriate model with correlation coefficients at 0.99. This novel algorithm can even create negative assortativity and managed to achieve assortativity values that spans over almost the entire theoretical range.

Place, publisher, year, edition, pages
PLOS , 2012. Vol. 7, no 8, e42679
National Category
Biological Sciences
Research subject
Natural sciences
Identifiers
URN: urn:nbn:se:his:diva-6472DOI: 10.1371/journal.pone.0042679ISI: 000307184700057PubMedID: 22876329Scopus ID: 2-s2.0-84864492191OAI: oai:DiVA.org:his-6472DiVA: diva2:559287
Available from: 2012-10-08 Created: 2012-10-08 Last updated: 2017-06-16Bibliographically approved
In thesis
1. Network analysis and optimization of animal transports
Open this publication in new window or tab >>Network analysis and optimization of animal transports
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis is about animal transports and their effect on animal welfare. Transports are needed in today’s system of livestock farming. Long transports are stressful for animals and infectious diseases can spread via animal transports. With optimization methods transport times can be minimized, but there is a trade-off between short distances for the animals and short distances for the trucks. The risk of disease spread in the transport system and disease occurrence at farms can be studied with models and network analysis.

The animal transport data and the quality of the data in the Swedish national database of cattle and pig transports are investigated in the thesis. The data is analyzed regarding number of transports, number of farms, seasonality, geographical properties, transport distances, network measures of individual farms and network measures of the system. The data can be used as input parameters in epidemic models.

Cattle purchase reports are double reported and we found that there are incorrect and missing reports in the database. The quality is improving over the years i.e. 5% of cattle purchase reports were not correctly double reported in 2006, 3% in 2007 and 1% in 2008. In the reports of births and deaths of cattle we detected date preferences; more cattle births and deaths are reported on the 1st, 10th and 20th each month. This is because when we humans don’t remember the exact number we tend to pick nice numbers (like 1, 10 and 20). This implies that the correct date is not always reported.

Network analysis and network measures are suggested as tools to estimate risk for disease spread in transport systems and risk of disease introduction to individual holdings. Network generation algorithms can be used together with epidemic models to test the ability of network measures to predict disease risks. I have developed, and improved, a network generation algorithm that generates a large variety of structures.

In my thesis I also suggest a method, the good choice heuristic, for generating non-optimal routes. Today coordination of animal transports is neither optimal nor random. In epidemic simulations we need to model routes as close to the actual driven routes as possible and the good choice heuristic can model that. The heuristic is tuned by two parameters and creates coordination of routes from completely random to almost as good as the Clarke and Wright heuristic. I also used the method to make the rough estimate that transport distances for cattle can be reduced by 2-24% with route-coordination optimization of transports-to-slaughter.

Different optimization methods can be used to minimize the transport times for animal-transports in Sweden. For transports-to-slaughter the strategic planning of “which animals to send where” is the first step to optimize. I investigated data from 2008 and found that with strategic planning, given the slaughterhouse capacity, transport distances can be decreased by about 25% for pigs and 40% for cattle. The slaughterhouse capacity and placement are limiting the possibility to minimize transport times for the animals. The transport distances could be decreased by 60% if all animals were sent to the closest slaughterhouse 2008. Small-scale and mobile slaughterhouses have small effect on total transport work (total transport distance for all the animals) but are important for the transport distances of the animals that travel the longest.

 

 

Place, publisher, year, edition, pages
Linköping University, 2012. 46 p.
Series
Linköping Studies in Science and Technology, Dissertation, ISSN 0345-7524 ; 1434
National Category
Biological Sciences
Research subject
Natural sciences
Identifiers
urn:nbn:se:his:diva-6492 (URN)978-91-7519-939-9 (ISBN)
Note

I Håkansson, N., Henningsson, M., Rönnqvist, M. & Wennergren U., June 2007 Route planning reduces the costs of animal transportation: Animal welfare versus economics. pp. 1044–048. Tartu, Estonia: XIII Int. Congr. Animal hygiene.

II Nöremark, M., Håkansson, N., Lindström, T., Wennergren, U. & Sternberg Lewerin, S., 2009 Spatial and temporal investigations of reported movements, births and deaths of cattle and pigs in Sweden. Acta Veterinaria Scandinavica 51(37).

III Nöremark, M., Håkansson, N., Sternberg Lewerin, S., Lindberg, A. & Jonsson, A., 2011 Network analysis of cattle and pig movements in Sweden: Measures relevant for disease control and risk based surveillance. Preventive Veterinary Medicine 99, pp 78 –90.

IV Håkansson, N., Jonsson, A., Lennartsson, J., Lindström, T. &Wennergren, U., 2010 Generating structure specific networks. Advances in Complex Systems (ACS) 13(02), pp 239–50.

V Lennartsson, J., Håkansson, N.,Wennergren, U. & Jonsson, A., 2012 SpecNet: a spatial network algorithm that generates a wide range of specific structures.(submitted manuscript 1).

VI Håkansson, N., Flisberg, P., Algers, B., Rönnqvist, M. & Wennergren, U., 2012 A strategic analysis of slaughterhouses and animal transportation in Sweden. (manuscript).

Available from: 2012-10-10 Created: 2012-10-09 Last updated: 2013-03-26Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMedScopus

Search in DiVA

By author/editor
Lennartsson, JennyHåkansson, NinaJonsson, Annie
By organisation
The Systems Biology Research CentreSchool of Life Sciences
In the same journal
PLoS ONE
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 853 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf