11 research outputs found
Augmented reality usage for prototyping speed up
The first part of the article describes our approach for solution of this
problem by means of Augmented Reality. The merging of the real world model and
digital objects allows streamline the work with the model and speed up the
whole production phase significantly. The main advantage of augmented reality
is the possibility of direct manipulation with the scene using a portable
digital camera. Also adding digital objects into the scene could be done using
identification markers placed on the surface of the model. Therefore it is not
necessary to work with special input devices and lose the contact with the real
world model. Adjustments are done directly on the model. The key problem of
outlined solution is the ability of identification of an object within the
camera picture and its replacement with the digital object. The second part of
the article is focused especially on the identification of exact position and
orientation of the marker within the picture. The identification marker is
generalized into the triple of points which represents a general plane in
space. There is discussed the space identification of these points and the
description of representation of their position and orientation be means of
transformation matrix. This matrix is used for rendering of the graphical
objects (e. g. in OpenGL and Direct3D).Comment: Keywords: augmented reality, prototyping, pose estimation,
transformation matri
Augmented Reality Implementation Methods in Mainstream Applications
Augmented reality has became an useful tool in many areas from space
exploration to military applications. Although used theoretical principles are
well known for almost a decade, the augmented reality is almost exclusively
used in high budget solutions with a special hardware. However, in last few
years we could see rising popularity of many projects focused on deployment of
the augmented reality on different mobile devices. Our article is aimed on
developers who consider development of an augmented reality application for the
mainstream market. Such developers will be forced to keep the application
price, therefore also the development price, at reasonable level. Usage of
existing image processing software library could bring a significant cut-down
of the development costs. In the theoretical part of the article is presented
an overview of the augmented reality application structure. Further, an
approach for selection appropriate library as well as the review of the
existing software libraries focused in this area is described. The last part of
the article outlines our implementation of key parts of the augmented reality
application using the OpenCV library
Data from: Environmental drivers and phylogenetic constraints of growth phenologies across a large set of herbaceous species
1. Because perennial herbs of temperate climates develop their aboveground parts every year anew, their success critically depends on the timing and speed of this growth (growth phenology). These parameters can play a role in species coexistence and may differ along environmental gradients. Still, we know little about them, as most phenological data come from observations of flowering and to a lesser degree leafing onset.
2. We collected data on growth phenology of about 400 perennial herbs in a botanical garden to make the results independent of local differences in climatic drivers as much as possible. Using these data, we determined species-specific parameters of Day of peak growth, Day of maturity, and two types of growth rates associated with the change in plant size. Environmental conditions in which these species occur in the field were assessed using Ellenberg indicator values, which express species' optima along gradients of moisture, nutrients and temperature.
3. Both timing and speed of growth estimated in the common garden were affected by light and moisture conditions of the habitats where the species typically occur. All parameters showed phylogenetic conservatism.
4. We identified two relationships among these parameters of growth phenology: (i) species with early peak growth had high relative growth rates in contrast to late species; (ii) tall species showed later peak growth than short species which more often grew early. The first relationship is associated with survival under forest canopy, where species are selected to grow early and fast before trees leaf out, which restricts their size. The latter is associated with (asymmetric) competition for light in open habitats, where the main selection factor is for tall stature, which cannot be attained early in the season.
5. Synthesis: We show that large differences in size growth dynamics among herbaceous species are constrained by a few key tradeoffs involving height at maturity, rate of growth, and time when maximum height is attained. These tradeoffs correspond to major selective forces acting on herbaceous plants in temperate climates
root biomass per pot half
Root foraging data for 37 plant species. The experiment was run in two years. Each row corresponds to a pot. In each pot, there was either no spatial gradient of nutrients, or shallow gradient or steep gradient (column "contrast"). Dry belowground biomass is reported for each half of the pot (root biomass content in the nutrients-poor half: column "lowconc_half_roots[g]"; root biomass content in the nutrients-rich half: column "highconc_half_roots[g]"); for pots with no gradient, identity of halves was chosen at random. Aboveground dry biomass and sum of the belowground halves are reported, too
Data from: Root foraging performance and life-history traits
Plants use their roots to forage for nutrients in heterogeneous soil environments, but different plant species vastly differ in the intensity of foraging they perform. This diversity suggests the existence of constraints on foraging at the species level. We therefore examined the relationships between the intensity of root foraging and plant body traits across species in order to estimate the degree of coordination between plant body traits and root foraging as a form of plant behavior. We cultivated 37 perennial herbaceous Central European species from open terrestrial habitats in pots with three different spatial gradients of nutrient availability (steep, shallow and no gradient). We assessed the intensity of foraging as differences in root placement inside pots with and without a spatial gradient of resource supply. For the same set of species, we retrieved data about body traits from available databases: maximum height at maturity, mean area of leaf, specific leaf area, shoot lifespan, ability to self-propagate clonally, maximal lateral spread (in clonal plants only), realized vegetative growth in cultivation and realized seed regeneration in cultivation. Clonal plants and plants with extensive vegetative growth showed considerably weaker foraging than their non-clonal or slow-growing counterparts. There was no phylogenetic signal in the amount of expressed root foraging intensity. Since clonal plants foraged less than non-clonals and foraging intensity did not seem to be correlated with species phylogeny, we hypothesize that clonal growth itself (i.e. the ability to develop at least partly self-sustaining ramets) may be an answer to soil heterogeneity. Whereas unitary plants use roots as organs specialized for both resource acquisition and transport to overcome spatial heterogeneity in resource supply, clonal plants separate these two functions. Becoming a clonal plant allows higher specialization at the organ level, since a typical clonal plant can be viewed as a network of self-sustainable harvesting units connected together with specialized
high-throughput connection organs. This may be an effective alternative for coping with spatial heterogeneity in resource availability
Data from: Root foraging performance and life-history traits
Plants use their roots to forage for nutrients in heterogeneous soil environments, but different plant species vastly differ in the intensity of foraging they perform. This diversity suggests the existence of constraints on foraging at the species level. We therefore examined the relationships between the intensity of root foraging and plant body traits across species in order to estimate the degree of coordination between plant body traits and root foraging as a form of plant behavior. We cultivated 37 perennial herbaceous Central European species from open terrestrial habitats in pots with three different spatial gradients of nutrient availability (steep, shallow and no gradient). We assessed the intensity of foraging as differences in root placement inside pots with and without a spatial gradient of resource supply. For the same set of species, we retrieved data about body traits from available databases: maximum height at maturity, mean area of leaf, specific leaf area, shoot lifespan, ability to self-propagate clonally, maximal lateral spread (in clonal plants only), realized vegetative growth in cultivation and realized seed regeneration in cultivation. Clonal plants and plants with extensive vegetative growth showed considerably weaker foraging than their non-clonal or slow-growing counterparts. There was no phylogenetic signal in the amount of expressed root foraging intensity. Since clonal plants foraged less than non-clonals and foraging intensity did not seem to be correlated with species phylogeny, we hypothesize that clonal growth itself (i.e. the ability to develop at least partly self-sustaining ramets) may be an answer to soil heterogeneity. Whereas unitary plants use roots as organs specialized for both resource acquisition and transport to overcome spatial heterogeneity in resource supply, clonal plants separate these two functions. Becoming a clonal plant allows higher specialization at the organ level, since a typical clonal plant can be viewed as a network of self-sustainable harvesting units connected together with specialized
high-throughput connection organs. This may be an effective alternative for coping with spatial heterogeneity in resource availability
Huang et al. JEcol-2017-0542.R1-growth phenology
Huang et al. JEcol-2017-0542.R1-growth phenolog