Lecture 1 - Cybernetics

Question 1

What’s the meaning of cybernetics?

Answer 1

Cybernetics is the study of control and connections in nature, science and society

Question 2

What is cybernetic systems?

Answer 2

Cybernetic systems
• Organisation is the formation of systems
• Cybernetic system: interacting structures and processes combine to perform a common function that is different from the functions of the separate components

Question 3

what are the 3 types of cybernetic system by complexity are characterised by functions:

Answer 3

component states, structure and connections, transmitted signals

Question 4

What is the definition of:

1) Deterministic systems
2) Probabilistic systems

Answer 4

• Deterministic systems - components interact in a predetermined way and response is predictable. e.g. washing machine
• Probabilistic systems - response can not be exactly predicted. e.g. weather

Question 5

Give the definition for the following:
• Closed system -
• Open system -  
• Elements of the interaction -
• Biological cybernetic systems -

Answer 5

• Closed system - the components interact only with each other, no environmental interaction
• Open system - components interact with environment as well
• Elements of the interaction - perception of signals from other systems using receptors such as eyes, ears, etc. Transmission of signals to other systems using effectors such as organs of speech, gestures etc
• Biological cybernetic systems - basic properties are: self-organising, self-regulation

Question 6

Give the definition for the following:
• Complexity -
• Determinism -
• Organisation -

Answer 6

• Complexity - large number of components, complex and interrelated connections between components
• Determinism - Probabilistic: large number of components, large number of connections between components, strong external influences
• Organisation - each component can be regarded as a system of lower-level components - complex two-way hierarchy. High level components control low level components

Question 7

What the defintion of Information

Answer 7

is any set of related data, any meaningful event which results in an action, the state of a system of
interest (think of suits and how they gather information!). Information reduces lack of knowledge.

Question 8

What is the information theory?

Answer 8

Information theory: Study of information - acquisition, transmission, storing and retaining, processing, measuring

Question 9

Define the following :

Message -
Signal -
Channel - (give an example)

Answer 9

Message - the transmitted information
• Signal - the physical carrier of the message
• Channel - the medium through which the signal propagates
e.g. (signal - channel), sound wave - air, light wave - optical fibre, electric signal - electric wire.

Question 10

What is the definition of the following:

• Alphabet -
• Encoding by transmitter -
• Recoding -
• Decoding by receiver -

Answer 10

Alphabet is a set of signals which can be used to send any message

• Encoding by transmitter - generation of signal which carries the message
• Recoding - altering the alphabet
• Decoding by receiver - extraction of the message form the signal

Question 11

what is the definition of the following:

Isomorphic signals -
• Noise -
• Storing and retaining information -
• Measuring information -

Answer 11

Isomorphic signals - physically different, carry same message
• Noise - communication system disturbances which modify the signal
• Storing and retaining information - memory is the ability of a system to store and retain information and to recall it for
later use
• Measuring information - unit of measurement is the bit

Question 12

define the following:
Control -
Regulation -

Answer 12

Control - actions effecting a system and aimed at reaching a specific goal
Regulation - control for maintaining a specific state or process

Question 13

What is the following?
• Cybernetic control system -
• Program -
• Reference -

Answer 13

Cybernetic control system - self contained in its performance monitoring and correction capabilities
• Program - the set of rules used to control a system
• Reference - the law describing how the controlled system must behave

Question 14

What is the the types of control system:

• Controlling subsystem -
• Controlled subsystem -

Define the following
- Connections -
• One-loop control -
• Closed-loop control -

Answer 14

Control system:
- Controlling subsystem - processing info, sends control messages
- Controlled subsystem - changes according to message received
- Connections - subsystems transferring information between the controlling and controlled subsystems
• One-loop control - execution of the control messages IS NOT monitored
• Closed-loop control - execution of the control messages IS monitored

Question 15

Explain the components of the Reflex arc and give a small explanation:

• Receptors -
• Afferent (sensory) neurones -
• Neural centre -
• Efferent (motor) neurones -
• Effectors -

Answer 15

Control system:
- Controlling subsystem - processing info, sends control messages
- Controlled subsystem - changes according to message received
- Connections - subsystems transferring information between the controlling and controlled subsystems
• One-loop control - execution of the control messages IS NOT monitored
• Closed-loop control - execution of the control messages IS monitored

Question 16

Define positive feedback
Give the significance of positive feedback loops
beneficial (example too):
detrimental (example too)

Answer 16

Positive feedback - control results in increased divergence of the controlled subsystem. Process accelerates until limiting constraints of the system are reached.

Significance of positive feedback loops:
Beneficial:
-Amplify vital processes
-Provide adaptation, fast response to external factors and transition from the initial state to another, more appropriate state
EXAMPLE: Products of food digestion:
•stimulate secretion of gastric juice
•more products of food digestion increased secretion of gastric juice
•more products of food digestion, etc

.Detrimental:
-Aggravate morbid conditions
EXAMPLE: Cardiac insufficiency reduces blood supply to the heart:
•the capacity of the heart to pump blood is reduced
•the supply of blood to the heart is further reduced
•the capacity of the heart to pump blood is reduced even more, etc.

Question 17

Define Negative feedback
Give the significance of Negative feedback loops
beneficial (example too):
detrimental (example too):

Answer 17

Negative feedback - the control results in balancing of the controlled subsystem. Ensures the quality and reliability of the control system.

• Significance of negative feedback loops:

• Ensure stability of body functions, resistance to external factors
• Basic mechanism of homeostasis, the balance of energy and metabolites in the body, the control of populations of species

EXAMPLE: Regulation of body core temperature
• Body temperature exceeds norm: heat loss from body, vasodilation, sweating, flat lying skin hairs.Reduce heat production, less movement and food consumption
• Body temperature falls below norm: reduce heat loss, vasoconstriction, standing hairs. Intensify heat production, shivering, metabolic efficiency
• Types of control: static and dynamic

Question 18

Define the following:
Model - 
Modelling - 
State the type of modeling:
1. mathematical model
2. physical model
3. biological model

Answer 18

Model - simplified physical or mathematical representation of a system used for its investigation
Modelling - methods for investigation of systems using their models

Types: mathematical, physical, biological
1• Mathematical model - mathematical description of some aspects of the real system
- uses mathematics and computers to produce information about studied system. e.g. regulation of blood glucose conc.
2• Physical model - material object performing similarly to the real system. e.g. electric circuit modelling transitional processes in a nerve fibre
3• Biological model - lab animal used to reproduce specific condition of the human body. e.g. investigation of infections, pharmaceuticals, poisons, etc.