1,886 research outputs found
Cross - fertilization between three different teaching modes for geo - informatics education
Objective of this study was to determine if the use and student appreciation of course
materials differs for native materials (materials that were developed for that course type in
which they are used) and foreign materials (materials that were developed for another course
type) and if the way the materials are used, (compulsory versus optional, interchangeable
versus the only source of information) affects the student appreciation.
A comparison was made between a face-to-face course, a blended learning course and a
distance course. The comparison was based on a questionnaire, the course evaluation and the
statistics from the digital learning environments. Results show no difference between native
and foreign course materials, but do however show the influence of the way the materials
were used. Appreciation for compulsory, non-interchangeable materials is higher than for
optional interchangeable ones, but even for this last category the general appreciation is high.
Distance students have the highest overall appreciation for study materials, followed by the
face-to-face students
Accounting for the alignment of interest and commitment in interfirm transactional relationships
Control in interfirm transactional relationships has, inter alia, the purpose of mitigating potential opportunistic behaviour. For an individual actor the power-base to exercise control over the (output of) the behaviour of another actor in the relationship is a contractual arrangement. From a contractual perspective control systems are designed, thus providing contractual instruments to align interests and to prevent future opportunistic behaviour from occurring. Transaction cost economics proves to be a powerful tool for designing these instruments, which from this theoretical perspective are based on 'credible commitments' and 'credible exit threats'. The paper argues that the design and potential use of these instruments are efficient in the presence of the legitimate mistrust for which they have to compensate. However, given fundamental uncertainty, these designs do not suffice in attenuating opportunism and have to be complemented by trust building. Drawing on insights from cognitive social psychology and sociology, the paper clarifies that in self-regulating processes of rational interaction guided by a principle of enlightened self-interest, trust is built via mutual relational signalling. Partners voluntarily and deliberately signal to each other that they are trustworthy. The paper argues and gives evidence that instrumental control system design embedded in an institutional environment and atmosphere is a necessary flank for a trust building process to work properly. The (interrelated) roles of accounting in a contractual realm as well as in self-regulating processes of relational signalling are examined
Object identification and characterization with hyperspectral imagery to identify structure and function of Natura 2000 habitats
Habitat monitoring of designated areas under the EU Habitats Directive requires every 6 years information on area, range, structure and function for the protected (Annex I) habitat types. First results from studies on heathland areas in Belgium and the Netherlands show that hyperspectral imagery can be an important source of information to assist the evaluation of the habitat conservation status. Hyperspectral imagery can provide continuous maps of habitat quality indicators (e.g., life forms or structure types, management activities, grass, shrub and tree encroachment) at the pixel level. At the same time, terrain managers, nature conservation agencies and national authorities responsible for the reporting to the EU are not directly interested in pixels, but rather in information at the level of vegetation patches, groups of patches or the protected site as a whole. Such local level information is needed for management purposes, e.g., exact location of patches of habitat types and the sizes and quality of these patches within a protected site. Site complexity determines not only the classification success of remote sensing imagery, but influences also the results of aggregation of information from the pixel to the site level. For all these reasons, it is important to identify and characterize the vegetation patches. This paper focuses on the use of segmentation techniques to identify relevant vegetation patches in combination with spectral mixture analysis of hyperspectral imagery from the Airborne Hyperspectral Scanner (AHS). Comparison with traditional vegetation maps shows that the habitat or vegetation patches can be identified by segmentation of hyperspectral imagery. This paper shows that spectral mixture analysis in combination with segmentation techniques on hyperspectral imagery can provide useful information on processes such as grass encroachment that determine the conservation status of Natura 2000 heathland areas to a large extent. A limitation is that both advanced remote sensing approaches and traditional field based vegetation surveys seem to cause over and underestimations of grass encroachment for specific categories, but the first provides a better basis for monitoring if specific species are not directly considered
Accounting for the alignment of interest and commitment in interfirm transactional relationships
Control in interfirm transactional relationships has, inter alia, the purpose of mitigating potential opportunistic behaviour. For an individual actor the power-base to exercise control over the (output of) the behaviour of another actor in the relationship is a contractual arrangement. From a contractual perspective control systems are designed, thus providing contractual instruments to align interests and to prevent future opportunistic behaviour from occurring. Transaction cost economics proves to be a powerful tool for designing these instruments, which from this theoretical perspective are based on 'credible commitments' and 'credible exit threats'. The paper argues that the design and potential use of these instruments are efficient in the presence of the legitimate mistrust for which they have to compensate. However, given fundamental uncertainty, these designs do not suffice in attenuating opportunism and have to be complemented by trust building. Drawing on insights from cognitive social psychology and sociology, the paper clarifies that in self-regulating processes of rational interaction guided by a principle of enlightened self-interest, trust is built via mutual relational signalling. Partners voluntarily and deliberately signal to each other that they are trustworthy. The paper argues and gives evidence that instrumental control system design embedded in an institutional environment and atmosphere is a necessary flank for a trust building process to work properly. The (interrelated) roles of accounting in a contractual realm as well as in self-regulating processes of relational signalling are examined
Using the right slope of the 970nm absorption feature for estimating canopy water content
Canopy water content (CWC) is important for understanding the functioning of terrestrial ecosystems.
Biogeochemical processes like photosynthesis, transpiration and net primary production are related to foliar
water. The first derivative of the reflectance spectrum at wavelengths corresponding to the left slope of the
minor water absorption band at 970 nm was found to be highly correlated with CWC and PROSAIL model
simulations showed that it was insensitive to differences in leaf and canopy structure, soil background and
illumination and observation geometry. However, these wavelengths are also located close to the water
vapour absorption band at about 940 nm.
In order to avoid interference with absorption by atmospheric water vapour, the potential of estimating
CWC using the first derivative at the right slope of the 970 nm absorption feature was studied.
Measurements obtained with an ASD FieldSpec spectrometer for three test sites were related to CWC
(calculated as the difference between fresh and dry weight). The first site was a homogeneous grassland
parcel with a grass/clover mixture. The second site was a heterogeneous floodplain with natural vegetation
like grasses and various shrubs. The third site was an extensively grazed fen meadow.
Results for all three test sites showed that the first derivative of the reflectance spectrum at the right slope of
the 970 nm absorption feature was linearly correlated with CWC. Correlations were a bit lower than those at
the left slope (at 942.5 nm) as shown in previous studies, but better than those obtained with water band
indices. FieldSpec measurements showed that one may use any derivative around the middle of the right
slope within the interval between 1015 nm and 1050 nm. We calculated the average derivative at this
interval. The first site with grassland yielded an R2 of 0.39 for the derivative at the previously mentioned
interval with CWC (based on 20 samples). The second site at the heterogeneous floodplain yielded an R2 of
0.45 for this derivative with CWC (based on 14 samples). Finally, the third site with the fen meadow yielded
an R2 of 0.68 for this derivative with CWC (based on 40 samples). Regression lines between the derivative
at the right slope of the 970 nm absorption feature and CWC for all three test sites were similar although
vegetation types were quite different. This indicates that results may be transferable to other vegetation
types and other sites
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