scholarly journals Kartlegging og verdisetting av naturtyper

2019 ◽  
pp. 191-214
Author(s):  
Geir Gaarder ◽  
Kristin Wangen

Mapping of habitats is central to preserve biodiversity in Norway. This article describes the historic development of the methodology used to classify and assign value to nature types, a process that has been going on for almost ten years. A positivistic view of science has characterized the process, especially over the last few years, both among the authorities and in central specialist fora. This article discusses several challenges related to the development of the methodology. It is especially critical of Parliament’s demand for value-free methodology, which it argues is in fact impossible. Further, it discusses the need to employ expert opinion and to describe uncertainty. It also criticizes the lack of analyses that expose possible model errors of the methodology. This is especially applicable with respect to relevance and precision, where high precision in the method may increase the risk of failing to achieve the objective. The article concludes that sufficient focus has not been placed on the challenges that appear in the intersection between natural science and practical management during the development of the new methodology for habitat mapping. This process has demonstrated the importance of broad competence, of being open about choices and acknowledging the consequences of these, and of having enough patience to develop a good methodology.

2001 ◽  
Vol 18 (10) ◽  
pp. 2565
Author(s):  
Valeri I. Karlov ◽  
Carlos E. Padilla ◽  
Keto Soosaar ◽  
Leslie E. Matson ◽  
Hon M. Chun ◽  
...  

Author(s):  
J. C. Russ ◽  
T. Taguchi ◽  
P. M. Peters ◽  
E. Chatfield ◽  
J. C. Russ ◽  
...  

Conventional SAD patterns as obtained in the TEM present difficulties for identification of materials such as asbestiform minerals, although diffraction data is considered to be an important method for making this purpose. The preferred orientation of the fibers and the spotty patterns that are obtained do not readily lend themselves to measurement of the integrated intensity values for each d-spacing, and even the d-spacings may be hard to determine precisely because the true center location for the broken rings requires estimation. We have implemented an automatic method for diffraction pattern measurement to overcome these problems. It automatically locates the center of patterns with high precision, measures the radius of each ring of spots in the pattern, and integrates the density of spots in that ring. The resulting spectrum of intensity vs. radius is then used just as a conventional X-ray diffractometer scan would be, to locate peaks and produce a list of d,I values suitable for search/match comparison to known or expected phases.


Author(s):  
K. Z. Botros ◽  
S. S. Sheinin

The main features of weak beam images of dislocations were first described by Cockayne et al. using calculations of intensity profiles based on the kinematical and two beam dynamical theories. The feature of weak beam images which is of particular interest in this investigation is that intensity profiles exhibit a sharp peak located at a position very close to the position of the dislocation in the crystal. This property of weak beam images of dislocations has an important application in the determination of stacking fault energy of crystals. This can easily be done since the separation of the partial dislocations bounding a stacking fault ribbon can be measured with high precision, assuming of course that the weak beam relationship between the positions of the image and the dislocation is valid. In order to carry out measurements such as these in practice the specimen must be tilted to "good" weak beam diffraction conditions, which implies utilizing high values of the deviation parameter Sg.


Author(s):  
Klaus-Ruediger Peters

Differential hysteresis processing is a new image processing technology that provides a tool for the display of image data information at any level of differential contrast resolution. This includes the maximum contrast resolution of the acquisition system which may be 1,000-times higher than that of the visual system (16 bit versus 6 bit). All microscopes acquire high precision contrasts at a level of <0.01-25% of the acquisition range in 16-bit - 8-bit data, but these contrasts are mostly invisible or only partially visible even in conventionally enhanced images. The processing principle of the differential hysteresis tool is based on hysteresis properties of intensity variations within an image.Differential hysteresis image processing moves a cursor of selected intensity range (hysteresis range) along lines through the image data reading each successive pixel intensity. The midpoint of the cursor provides the output data. If the intensity value of the following pixel falls outside of the actual cursor endpoint values, then the cursor follows the data either with its top or with its bottom, but if the pixels' intensity value falls within the cursor range, then the cursor maintains its intensity value.


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