Alps - 17/12/24 Flashcards
what is a Server
A computer network responsible for managing and sharing resources, include file, print, application
what is the Switched Hub
Acts as a single connection point for devices on a network.
It forwards data packets to destination using each Packets Address.
Most hubs support load balancing so data packets are forwarded via different network segments based on traffic patterns.
What is a Media Converter
A hardware device that allows 2 dissimilar media types to connect with each other. May involve connecting a fibre optic cable and a copper cable.
What is an IP Address
Devices that communicate using internet are assigned an unique IP Address.
Is used to identify the device from another on the internet.
Networks will route messages using IP Address of the destination.
Consists of 32 bits formatted as 4 Octets.
Numbers can range from 0-255 (per octet) in decimal.
What is a MAC Address
(Media access control address
Allocated to a network interface card when it is manufactured is unique to it.
Made up of 6 two-digit Hexadecimal numbers, separated by colons.
P2P v Client Server Network
P2P= All computers on the network have equal status.
Allows hardware and software to function without the need for any dedicated server devices.
Each computer is a supplier and consumer of resources.
Each node is in charge of its own security.
Client= Used in Large organisations.
one computer file saver will carry out file storage, backup, provide application software and printer management.
All computers connected to server via a switch or hub.
Ring Network Topology
Consists of a number of nodes connected without the need for a file saver.
each node is connected to 2 other adjacent nodes.
A token is passed from node to node.
Difficult to add a new node to this network.
Data travel for large distances can lead to problems with the data signal, this tends to degenerate and weaken.
Star Network Topology
Has a central file saver.
Each node is connected to the file saver by its own cable.
Host computer controls all communication.
If node fails, network can still operate as only affects that node.
Adding a new node is only a matter of connecting it to the hub if there is capacity.
OSI - Open System Interconnection Model
Provides a framework for data to be transferred between network computers.
Model works even if different data formats or different types of networks are communicating.
Developed by the ISO (international standards organisation)
OSI - benefits
Any hardware that meets the OSI standard will be able to communicate with any other hardware that also meets the standard (same with software).
Consumers are given a wider choice, hardware/software from any manufacturer will work together, independent of country.
Not dependent of the operating system.
Error handling in each layer.
different layers can operate automatically.
Basic Rules of OSI
Top 3 Layers are grouped together and called the ‘Application set’.
Application set: mainly concerned with controlling how various applications currently running are making use if the network.
Bottom 4 layers are called the ‘Transport set’.
Transport set: only concerned with passing info through the network.
Each layer can only communicate with the layer above or below it.
OSI - 1. Application layer
Top Layer.
Only concerned with presenting info in human friendly way.
relevant to all typed of devices that use inbuilt computer processors, e.g., Mobile Phones
OSI - 2. Presentation layer
Concerned with presenting info to the various electronic devices in the correct format.
Can implement encryption.
May compress/decompress info.
OSI - 3. Session layer
A session begins when an application wants to make a connection to a remote server.
Opens a temporary channel between the 2, to allow communication.
Can have more than one session running at a time.
OSI - 4. Transport layer
Divides info into convenient sized packets and sent on different routes.
Packets may arrive in a different order, they will be reassembled at the destination point into the order they were sent.
Layer can also check for errors.
OSI - 5. Network layer
Works out best rout for the packets to use.
Every computer has an unique IP Address to each packet.
Reads the address of incoming packets to a computer and if they are destined for that computer, it allows them through.
OSI - 6. Data Link layer
Each Packet is converted into a series of bits.
Converts incoming bits back into complete packets.
Bits can be corrupted of flipped and the layer will attempt to spot these reversals and fix them.
OSI - 7. Physical layer
Bits and Bytes have to be converted into physical effect so they can be transmitted.
This layer will convert the abstract ‘Data Bit’ inside the computer into a physical effect of some kind.
Tuning Test
Used to assess the ability of a machine to exhibit intelligent behaviour which could not be distinguished from that of a human.
Critics challenge test as a measure of intelligence as it doesn’t assess the correctness of responses, only how similar to human response.
Tuning test - natural network modelling and Ai
Computational models used in computer science to model a primitive brain.
Tuning test - Natural network modelling and Ai
Main Features
Consists of a number of artificial neurons called units.
Number of units could vary depending on the complexity of the neural network.
They are arranged in layers.
Input units will receive info from the outside world.
Hidden units will process input from the input unit.
Output provides a response from the network representing any info it has learned.
Most cases, the neural networks are fully connected.
Each connection is weighted and algorithms are used to calculate the weighted sum of any input to generate an output value.
Neural networks learn by itself, no need to explicitly program.
How does a neural network learn?
Pattens of info will enter the network via the input units, triggering layers of hidden units until they arrive at the output units.
Inputs into a unit are multiplied by the weightings.
Weighted inputs are added together and if sum is above given threshold value, that unit will trigger units connected - feedforward network.
Feedback is important - used to support learning - Backpropagation.
The output produced by the neural network is compared to the output it was meant to produce.
Expert Systems.
Knowledge based systems.
An application of AI - in this the knowledge of a human expert is made available through a computer package.
used in a narrow field of knowledge - knowledge domain.
Expert systems - key components
An expert is an experienced practitioner in a particular field, e.g., a medical specialist, repair technician or financial analyst.
Initial building stage is called knowledge acquisition.
Knowledge of human expert is programmed into the expert system and represented using rules and facts.
Result is the creation of a knowledge base - this holds knowledge about the domain, Can be stated as a series of IF-THEM-ELSE rules.
