- ... mesh2.1
- The term ``background
mesh'' will be explained in Section 3.3.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... method2.2
- See
Section 4.1.2.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... points3.1
- See
Chapter 5 for a description of the Voronoi diagram
and the Delaunay properties.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... M-matrix3.2
- A real,
nonsingular matrix where
and .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... space3.3
- A slightly different concept of control space is given in
[55].
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... representation3.4
- An image
which consists of pixels in two and voxels in three dimensions.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...
point4.1
- Quadrilateral/hexahedral elements require more points.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... mesh4.2
- For instance see Section 5.6.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...
algorithms4.3
- Section 5.3.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... topology4.4
- This is strictly only valid for a
unique Delaunay Triangulation, Section 5.4
and 6.4.3.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... points4.5
- The constrained Delaunay
Triangulation can only be guaranteed in two dimensions, see
Section 5.5.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... quality4.6
- The
max-min and min-max-min Delaunay properties are discussed in
Section 5.1.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ... four5.1
- If in three dimensions more than four
Voronoi boxes are incident at a Voronoi point, the Delaunay Triangulation
is non-unique.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
- ...
NP-complete5.2
- Many outstanding and famous problems exist in computer
science for which no deterministic polynomial time algorithms are known.
Exponential time algorithms are useless regardless of the speed of a
computer, because finding a solution is in any case too expensive.
Problems which can be solved by deterministic algorithms in polynomial
time are said to be in P. Problems which can only be solved by
nondeterministic algorithms in polynomial time are said to be in NP.
In other words if the solution is not efficiently found but guessed
and then checked for validity by a polynomial time algorithm the
problem is in NP.
The trouble is that no one has been able to prove that a problem is in NP
and not in P. It is unclear whether an efficient deterministic polynomial
time algorithm for a problem in NP remains undiscovered or simply does not
exist. Problems exist which can be proven to represent all problems in NP.
These problems are said to be NP-complete. If an NP-complete problem could
be solved by a deterministic polynomial time algorithm, it would be proven
that P=NP. This would mean that to all outstanding and famous problems
efficient but undiscovered solutions exist. Otherwise one must rely on
heuristics and hope that they do not fail for most practical instances
of the problem. Some well known NP-complete problems are
traveling-salesman, Hamilton-cycle, satisfiability, and longest-path.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.