Configuration?

Transition Styles

None - Fade - Slide - Convex - Concave - Zoom

Themes

Black (default) - White - League - Sky - Beige - Simple
Serif - Blood - Night - Moon - Solarized

𝄞 Music is a language 𝄞

Talk

Hear

See

Communication

Emotions

It's not always soft!

Soft but ...

Feel the anger...

𝄞 Still a language 𝄞

Alphabet

Notes

do re mi fa sol la si

Scale

Pitch

Harmony Search Algorithm

Milad As (Ravexina)
Dec 2018

Same old usual things

Same old usual things

Near optimom solution
Reasonable time
Reasonable memory usage

Rules, Randomness

SA, GA, Tabu

Is it possible to develop a new heuristic algorithm with better performance

Better solutions!

Fewer iterations!

Than existing heuristic algorithms?

Music is one of the most satisfying processes generated by human endeavors

A new heuristic algorithm derived from an artificial phenomenon found in musical performance namely the process of "searching for better harmony", can be introduced.

Melody

A sequence of single notes that is musically satisfying.

Harmony

When 2 or more notes play together at the same time in “harmony” with each other.

Harmony

Music harmony is a combination of sounds considered pleasing from an aesthetic point of view.

Fantastic Harmony

Musical performances
seek a best state determined by aesthetic estimation!

Optimization algorithms seek a best state.

Best state?

Global optimum

Minimum cost

Maximum benefit

Determined by objective function

Sounds can be improved for better aesthetic estimation

Through practice after practice

Values for better objective function evaluation can be improved

Iteration by iteration

comparison between optimization and musical performance

Steps in the procedure of HS are as follows:

Step 1. Initialize a Harmony Memory (HM).

Step 2. Improvise a new harmony from HM.

Step 3. If the new harmony is better than minimum harmony in HM, include the new harmony in HM, and exclude the minimum harmony from HM.

Step 4. If stopping criteria are not satisfied, go to step 2.

Consider this simple example

Problem!

HMCR

Harmony memory consideration rate

PAR

[1, 2, 4, {6}, 7, 9]

An Example

Possible values of an instrument (a variable) is:
{C, D, E, F, G}

HMCR is 0.95, PAR is 0.10
The instrument now has: {C, E, G} in HM.

All In One

Basic Flowchart

HS incorporates the structure of existing heuristic methods.

Preserve history of past vectors

Vary HMCR

Manages several vectors simultaneously

Results obtained from various HS applications

Any question?

Code

Min

TSP

TSP Results

Reference:

Geem, Zong W. Kim, Joong H. Loganathan, G.V. "A New Heuristic Optimization Algorithm: Harmony Search." Simulation [USA] 2001. Print.

Thank you for your attention