Remote sensing methodologies could contribute to a more sustainable agriculture, such as monitoring soil preparation for cultivation, which should be done properly, according the topographic characteristics and crop’s nature. The objectives of this work are (1) demonstrate potential unmanned aerial vehicle (UAV) technology in acquisition 3D data before after tillage, quantification mobilised vo...

Let K be an abelian group and G be a connected graph, both finite. Using basic properties of circulations, we show that it is easy to generate uniformly random K-circulations on G. This leads to efficient algorithms for computing the cut edges, cut edge-pairs, and cut vertices of a graph; for example, the cut edges are “usually” the edges where a random circulation vanishes. In the distributed ...

Let S be a cut of a simple connected graph G. If S has no proper subset that is a cut, we say S is a minimal cut of G. To a minimal cut S, a connected component of G − S is called a fragment. And a fragment with no proper subset that is a fragment is called an end. In the paper ends are characterized and it is proved that to a connected graph G = (V, E), the number of its ends Σ ≤ |V (G)|.

Quantitative measurements of tumor in general and tumor volume in particular, become more realistic with the use of Magnetic Resonance imaging, especially when the tumor morphological changes become irregular and difficult to assess by clinical examination. However, tumor volume estimation strongly depends on the image segmentation, which is fuzzy by nature. In this paper a fuzzy approach is pr...

In the study of approximation algorithms, there are many useful techniques that are demonstrated in the analysis of cut problems. Given a graph G = (V,E) with an assignment of weights to edges w : E → R+ a cut is a set E′ ⊆ E, whose removal from the graph will partition the vertices into two disconnected sets. For two vertices, s, t ∈ V , an s− t cut is the one that creates a partition with s a...

Quantitative measurements of tumor in general and tumor volume in particular, become more realistic with the use of Magnetic Resonance imaging, especially when the tumor morphological changes become irregular and difficult to assess by clinical examination. However, tumor volume estimation strongly depends on the image segmentation, which is fuzzy by nature. In this paper a fuzzy approach is pr...

In the Maximum Cut problem, we are given a weighted graph G = (V,E,W ). The goal is to find a partitioning (S, S̄), S ⊂ V of the graph so as to maximize the total weight of edges in the cut. Formally the problem is to find f : V → {0, 1} which maximizes∑ij∈E:f(i)6=f(j) wij . In homework #1, we already saw a greedy 1/2-approximation algorithm for this problem. Now let’s examine a potential LP for...

Abstract. We present a Branch-and-Cut algorithm where the volume algorithm is applied instead of the traditionally used dual simplex algorithm to the linear programming relaxations in the root node of the search tree. This means that we use fast approximate solutions to these linear programs instead of exact but slower solutions. We present computational results with the Steiner tree and Max-Cu...

The exploration of geological composition, e.g. underground flow path, is a significant step for oil and gas search. However, to extract the structural geological composition from the volume, neither the classic volume exploration methods, e.g. transfer function design, nor the traditional volume cut algorithms can be directly used due to its three natural properties, various compositions, disc...