We study the inapproximability of the induced disjoint paths problem on an arbitrary n-node m-edge undirected graph, which is to connect the maximum number of the k sourcesink pairs given in the graph via induced disjoint paths. It is known that the problem is NP-hard to approximate within m 1 2 −ε for a general k and any ε > 0. In this paper, we prove that the problem is NP-hard to approximate...

Functional structural botanical tree models are one of the most difficult models in biology. We introduce IMapple, a model for ‘Golden Delicious’ apple (Malus × domestica) trees based on source-sink descriptions of plant resources. Our model uses precise geometrical representations with high quality polygonal meshes and geometric details. We introduce a novel simulation algorithm that provides ...

Short term experiments were conducted with vegetative soybean plants (Glycine max L. Merr. ;Ransom' or ;Arksoy') to determine whether sourcesink manipulations, which rapidly changed the ;demand' for sucrose and partitioning of photosynthetically fixed carbon into starch, were associated with alterations in activities of sucrose-P synthase and/or cytoplasmic fructose-1,6-bisphosphatase in leaf e...

In several applications of network flows, additional constraints have to be considered. In this paper, we study flows, where the flow particles have an orientation. For example, cargo containers with doors only on one side and train coaches with 1st and 2nd class compartments have such an orientation. If the end position has a mandatory orientation, not every path from source to sink is feasibl...

The two-phase theory for compaction and damage employs a nonequilibrium relation between interfacial surface energy, pressure, and viscous deformation, thereby providing a model for damage (void generation and microcracking) and a continuum description of weakening, failure, and shear localization. Here we examine the application of this theory to the problem of generating platelike behavior fr...

Given a graph G = (V,E) and k source-sink pairs {(s1, t1), . . . , (sk, tk)} with each si, ti ∈ V , the Min-Sum Disjoint Paths problem asks to find k disjoint paths connecting all the source-sink pairs with minimized total length, while the Min-Max Disjoint Paths problem asks for k disjoint paths connecting all the sourcesink pairs with minimized length of the longest path. We show that the wei...

(Assimilate partitioning in leaves of the raffinose-storing herb Lamium album L.: the effects of altering sourcesink balance). In Lamium album, sucrose and raffinose-family oligosaccharides are the major products of photosynthesis that are stored in leaves. Using gas analysis and CO 2 feeding, we compared photosynthesis and the partitioning of recently-fixed carbon in plants where sink activity...