User Tools

Site Tools


T-720-ATAI-2016 Main


Lecture Notes, F-12 26.02.2016

Belusov-Zhaboutinsky Reaction

Simulated Belousov-Zhabotinsky Reaction. Source: Wikipedia

Belusov-Zhaboutinsky Reaction

What it is A chemical reaction discovered in 1950.
Why it's important Great visual example of the kind of emergent patterns can be created through auto-catalysis (chemical in this case). One of the first (the first?) scientifically published example of emergence identified as such.
Real version on Youtube

How the Belusov-Zhaboutinsky Reaction Works

Belousov-Zhabotinsky Reaction
A Belousov–Zhabotinsky reaction, or BZ reaction, is one of a class of reactions that serve as a classical example of non-equilibrium thermodynamics, resulting in the establishment of a nonlinear chemical oscillator. Wikipedia

Cellular Automata

What it is An algorithmic way to program interaction between (large numbers of) rule-determined “agents” or cells. Wikipedia
Why it's important Powerful method to explore the concept of emergence. Also used for simulating the evolution of complex systems.
Explicates Interaction of rules.
Typical manifestation 1D or 2D grid with cell behavior governed by rules of interaction. Each cell has a scope of what it “sees” (its range of “causal ties”).

CA Example 1

In this example
Green –> Brown IF one or more are true:
* There are more than 20 green patches around and lifetime exceeds 30
* There are less than 12 green patches around and lifetime exceeds 20
* The number of surrounding green patches > 25
* Lifetime > 60 ticks
Brown –> Green IF both are true:
* Number of surrounding green patches > 8 and heir lifetime combined > 80
* Number of surrounding brown patches > 10

Stephen Wolfram's CA Work

Book A New Kind of Science.
Why it's important Major analysis of rules for 1-D CAs. Most comprehensive work on CAs to date.
Rule 30 Wikipedia

Symbols, Meaning & Understanding

What are Symbols? Peirce's Theory of Semiotics (signs) proposes 3 parts to a sign: a sign/symbol, an object, and an interpretant. Example of symbol: an arbitrary pattern, e.g. a written word. Example of object: an automobile. Example of interpretant: what you see in your mind's eye when you read the word “automobile”. The last part is the most complex thing, because obviously what you see and I see when we read the word “automobile” is probably not exactly the same.
“Symbol” Peirce used various terms for this, including “sign”, “representamen”, “representation”, and “ground”. Others have suggested “sign-vehicle”. What is mean in all cases is a pattern that can be used to stand for something else, and thus requires an interpretation to be used as such.
Peirce's Innovation Detaching the symbol/sign from the object signified, and introducing the interpretation process as a key entity. This makes it possible to explain why people misunderstand each other, and how symbols and meaning can grow and change in a culture.
Understanding Understanding of a particular phenomenon phi is the potential to perform actions and answer questions with respect to phi. Example: Is an automobile heavier or lighter than a human? For this computational models can be used.
Meaning This is far from settled, and philosophers are still grappling with the topic. It is of course highly relevant to AI, especially AGI.
Current Approach Meaning stems from two main sources. Firstly, acquired and tested models form a graph of relations; the comprehensiveness of this graph determines the level of understanding that the models can support with respect to a particular phenomenon. Meaning is not possible without (some level of) understanding. Secondly, meaning comes from the context of the usage of symbols, where the context is provided by (a) who/what uses the symbols, (b) in what particular task-environment, using ( c) what particular syntactic constraints.
Prerequisites for using symbols A prerequisite for communication is a shared interpretation method, shared interpretation of syntax (context), and shared knowledge (object).
Where the Symbols “are” When we use the term “symbol” in daily conversation we typically are referring to its meaning, not its form (sign). The meaning of symbols emerges from the interpretation process which is triggered by the contextual use of a sign: A sign's relation to forward models, in the pragmatic and syntactic context, produces a meaning - that which is signified. Thus, more than being “stored in a database”, symbols are continuously and dynamically being “computed based on knowledge”.
/var/www/ailab/WWW/wiki/data/pages/public/t-720-atai/atai-16/lecture_notes_f-14_26.02.2016.txt · Last modified: 2017/12/06 13:30 by thorisson