Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2004
Abstract
Using Singular System Analysis (SSA), we extract a collection of significant long-term components (with dominant periods of at least 3 years) for a large number of river runoff records.At first glance, these long-term modes are a distinct feature of this variable, not contained in precipitation and temperature, and not easily correlated to commonly known long-term indices (NAO, SOI, NHT, SUN, etc.). However, low-pass filtered versions of these time series exhibit strikingly similar behavior, like common maxima, within a region (such as Southern Germany), pointing to a common origin.Although not an unequivocal example for synchronization, we quantify the degree of synchronization as a function of the regional extent of the data and propose a mechanism, stochastic resonance, discussed in climate dynamics, which is able to produce this collective behavior despite the lack of deterministic drivers. We also comment on air pressure-induced teleconnections between the different large scale oscillations in the climate system.
Authors
Line Hoem Erlend Ystrøm HaartveitAbstract
Major driving forces among companies in the forest products industry are mergers and acquisitions and narrowing the strategic focus to core competencies. The combined effect is that the mutual dependency in customer-supplier relationships increases, and that the share of the total value added provided by each actor decreases. Standard techniques for process mapping are intended as the first step in process improvement. Order processes, extending from identification of demand to fulfilment of demand, commonly cross company borders. The result is an increasing need for inter-company coordination to increase efficiency of material flows. This paper presents preliminary results from the mapping of the order process between a Norwegian retail chain and its major supplier of solid wood products. A model intended for supply chain mapping has been modified and applied to this particular case. One outcome of the mapping is that a detailed overview of the process can reveal simple solutions for process improvement, as individual actors rarely focus on optimising their combined process, but rather have an internal focus. The mapping also provides a basis for evaluation of existing performance measurements, and for development of new measurements with a focus on improving the actors’ combined order process.
Abstract
No abstract has been registered
Authors
Svein Ole Borgen Anne Moxnes JervellAbstract
No abstract has been registered
Authors
Alhaji Jeng Trond Knapp Haraldsen Nils Vagstad Arne Grønlund Steinar TveitnesAbstract
Nitrogen, fertilizer, meal
Authors
Alhaji S. Jeng T. K Haraldsen N. Vagstad A. Grønlund S. TveitnesAbstract
No abstract has been registered
Abstract
Genetic variation in three multiallelic loci was analysed with Temperature Gradient Gel Electrophoresis in order to assess the genetic population structure of Venturia tremulae var. tremulae in order to understand the evolutionary potential of the pathogen against resistance breeding. Also the identification of the fungus was verified with molecular analysis of reference isolates. The Fst and Gst values were very low indicating no substructuring or restrictions to gene flow between Fennoscandian populations of V. tremulae. The results imply high epidemiological efficiency of the fungus and therefore continuous breeding programme should be implemented for Venturia resistance of aspen.
Abstract
No abstract has been registered
Abstract
Ecosystems as objects of natural sciences are often difficult to understand, as an object of traditional management they are sometimes easy to utilize. Computer-based modeling offers new tools to study this apparent paradox.We propose an interactive framework from which the traditional approach based on dynamic system theory can be challenged for living systems: Models derived on the basis of the state concept have not (yet?) allowed predictions that derive novel management competence relevant for the altered boundary conditions of ecosystems. Here a concept of interaction as currently used in information sciences serves as starting point for deriving models more appropriate for ecosystems.An application and test of this concept consists in a search for signatures of interaction in environmental and ecological time series. Confronted with the notorious lack of detailed process understanding, it is plausible to rely on time series analysis techniques. The intricate nature of typical multivariate data sets from ecosystems immediately suggests a preference for nonlinear techniques, and among them temporally local methods, able to detect even subtle changes in the underlying dynamics.We shortly introduce a couple of these methods, which have been demonstrated to be appropriate for time series exceeding minimal length requirements. This is exemplified by recurrence quantification analysis. In addition we present methods to quantify the memory content (Hurst analysis) and complexity of data sets (defined in an informationtheoretic context).Time series analysis of extended environmental and ecological data sets can give detailed structural insights, monitors subtle changes undetectable otherwise, forms the basis for further inferences and provides rigorous model testing on all scales. The success of dynamic system theory when applied to non-living environmental data is strikingly contrasted by the difficulties of the same method when dealing with ecological data We conjecture that this difference reflects the extent to which interaction has been disregarded for ecosystems.
Abstract
No abstract has been registered