The Naive Mix is a new supervised learning algorithm based on sequential model selection. The usual objective of model selection is to nd a single proba-bilistic model that adequately characterizes, i.e. ts, the data in a training sample. The Naive Mix combines models discarded during the selection process with the best{{tting model to form an averaged probabilistic model. This is shown to impr...

In this work we deal with the problem of learning a maximum weighted (k + 1)order decomposable graph coarser than a given maximal k-order decomposable graph. An Integer Linear Programming formulation for the problem has been recently proposed and used in order to solve instances of the problem with a moderate number of vertices [8]. However, as the problem is known to be NP-hard, it is of pract...

We study two decomposition problems in combinatorial geometry. The first part of the thesis deals with the decomposition of multiple coverings of the plane. We say that a planar set is cover-decomposable if there is a constant m such that any m-fold covering of the plane with its translates is decomposable into two disjoint coverings of the whole plane. Pach conjectured that every convex set is...

A graph is locally irregular if any pair of adjacent vertices have distinct degrees. decomposition a G D such that every subgraph H∈D irregular. said to be decomposable it admits decomposition. We prove split can decomposed into at most three subgraphs and we characterize all graphs whose one, two or subgraphs.

A new method of model registration is proposed using graphical templates. A graph of landmarks is chosen in the template image. All possible candidates for these landmarks are found in the data image using local operators. A dynamic programming algorithm on decomposable subgraphs of the template graph nds the optimal match to a subset of the candidate points in polynomial time. This combination...

A signed graph (G,Σ) is a G together with set Σ⊆E(G) of negative edges. circuit positive if the product signs its edges positive. balanced all circuits are The frustration index l(G,Σ) minimum cardinality E⊆E(G) such that (G−E,Σ−E) balanced, and k-critical l(G,Σ)=k l(G−e,Σ−e)<k, for every e∈E(G). We study decomposition subdivision critical graphs completely determine t-critical graphs, t≤2. Cri...

Let S = {K1,3,K3, P4} be the set of connected graphs of size 3. We study the problem of partitioning the edge set of a graph G into graphs taken from any non-empty S′ ⊆ S. The problem is known to be NP-complete for any possible choice of S′ in general graphs. In this paper, we assume that the input graph is cubic, and study the computational complexity of the problem of partitioning its edge se...

An antimagic labeling of a connected graph with m edges is an injective assignment of labels from {1, . . . , m} to the edges such that the sums of incident labels are distinct at distinct vertices. Hartsfield and Ringel conjectured that every connected graph other than K2 has an antimagic labeling. We prove this for the classes of split graphs and graphs decomposable under the canonical decomp...

A new method of model registration is proposed using graphical templates. A graph of landmarks is chosen in the template image. All possible candidates for these landmarks are found in the data image using local operators. A dynamic programming algorithm on decomposable subgraphs of the template graph finds the optimal match to a subset of the candidate points in polynomial time. This combinati...

‎Recently‎, ‎some techniques such as adding whiskers and attaching graphs to vertices of a given graph‎, ‎have been proposed for constructing a new vertex decomposable graph‎. ‎In this paper‎, ‎we present a new method for constructing vertex decomposable graphs‎. ‎Then we use this construction to generalize the result due to Cook and Nagel‎.