10/11/99 Version | www.cs.ucla.edu/~klinger/pami/exer2.html |
CS 276A | Pattern Analysis and Machine Intelligence | ||||
A. Klinger | Fall 1999 | ||||
0. Write a question about Pattern Analysis, readings, or project. (The question can reflect thought about a fundamental issue.) .
1. Features' meaning involves decisions. Explain what a feature is.
Give a definition of the term.
2. Choose a real pattern domain. Describe what could be ideal, prototype,
template or paradigm patterns there. Indicate what could cause variation
from such items.
3. The Bayes decision rule involves maximum values of a probability. If
the symbol x represents a vector associated to a real pattern,
and there are n different classes it could be from, write out the
probabilities and express the rule in terms of them. (Hint: begin with
conditional probability; consider classes as numbers 1, 2, ..., n)
4. There are (a. ten; b. ten million) given values of seventy-coordinate
patterns from five classes. Describe the advantages and
disadvantages of Nearest Neighbor and Nearest Prototype decision rules
for these two situations.
5. If the 4.a information is available, a. what can be said about the
utility of the data for describing the pattern sets? If
we also know that only one class of
pattern type is present, b. what can be said now (and what are
any necessary assumptions)?
6. Symbols and signs present images
that communicate information. Examples depict "skull and crossbones"
signifying "poison" and "several curves" meaning "winding road".
Choose a pattern of this type from any area; nonvisual examples,
e.g., auditory, are fine.
Show how the "element of a set of items that
can in some useful way be treated alike" definition applies to your
choice.
7. Dice and cards transform numbers and images into symbols via word
descriptors. Make up a list of special terms that help people recognize
patterns in the play of games involving those items.
8. Mathematics is a "science of patterns" according to K. Devlin and
L. Steen. Support their belief with an example.
9. The Greeks knew that an integer (they had only positive ones) cubed could
be represented as the sum of adjacent odd numbers. E.g., 8 as 5 +
3, 27 as 11 + 9 + 7. Find the representation of 73. From it
describe a feature of integers that helps establish this general truth.
10. The Game of Life due to J. Conway (Scientific
American, Oct. 1970, p. 120) involves three rules governing behavior
of elements on an array of arbitrary size nxn. "Born" elements
mark some previously blank place in the array. "Die" is what happens to
an element that fails to exist in the next "generation"; some persist.
The rules involve the eight neighbors. Those elements with: a) two or three
neighbors survive; b) four or more neighbors die from overcrowding (and are
removed in the subsequent array), while those with no or one vanish because
of isolation. Any empty array place with exactly three elements in the
eight neighbors is a birth location: an element appears there in the
next iteration. Two-by-two patterns persist; one-by-three and three-by-one
alternate in sequence; many other patterns that persist (or travel) are
known. Simulate five or more iterations of this game on an array with
side equal to or greater than six. Did you find any interesting
patterns?