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Flashcards

A2 CCEA Digital Technology (Whole course)

Abbie Welch Digital Technology A level English 82 cards

Cards in this deck (82)

  1. 1NETWORKSNETWORKS
  2. 2What is a LAN?-A LAN is a local area network. It is used over a small geographical area e.g. office. It uses cables it provides services for a single operation
  3. 3What is a WAN?- WAN is a wide area network, It is used over a large geographical area. It requires a telecommunication link. It provides services globally
  4. 4What is a MAN?- MAN is used in a highly-populated area, It's smaller than a WAN and Larger than a LAN. It provides services for a community
  5. 5describe the purpose of a network cardA network card connects a node to a LAN to communicate with the file server and other nodes, Provides a port for an ethernet cable to connect
  6. 6describe the purpose of a serverManages network resources e.g. peripherals, printers etc. and processes requests from other nodes
  7. 7describe the purpose of a switched hubIt acts as a connection point for a number of network nodes
    It checks the IP address of a data packet and
    forwards it to the intended recipient using the optimal route
  8. 8describe the purpose of a repeaterIt regenerates a data transmission signal which has been attenuated
    Used over long distances
  9. 9• describe the purpose of a wireless access pointUsed to connect a node using wifi/Bluetooth in a hotspot using radio transmitters
  10. 10• describe the purpose of a media converterIt allows 2 dissimilar devices to connect. it changes physical signals from 1 media type to another
  11. 11• describe the purpose of an IP addressIt defines the connection address of a node on the internet
    Its set by the ISP it's linked to the physical location of the device and it updates the location of the device
    It uses 4 bytes
  12. 12• describe the purpose of a media access control (MAC) address;it identifies the network interface cards address uniquely on a LAN
    It uses 6 bytes.
    Each address has a fixed MAC address, set by the manufacturor and embedded on the Network interface card
  13. 13describe the features of a peer-to-peer (P2P)There is no central hub
    All nodes have equal status
    Each node is a consumer and supplier of resources
  14. 14describe the features of a server-based networkA central node controls the network and resources
    Each node has to request resources from the server
    Remote software upgrades are possible
  15. 15evaluate the bus network topologyAll nodes are connected using a backbone
    There are terminators at each end of the backbone
    Data can travel in both directions
    Less reliable as if backbone fails the whole network fails if a single cable fails then only that device is affected
    Less secure as all nodes can access the data on the backbone
    Anode sends data to another node by placing it on the backbone
  16. 16evaluate the star network topologyAll nodes are connected to a central hub by their own cable. It controls communication and the transfer of data.
    Most secure as the data is sent to the hub to the node directly. It controls all the security. Only the intended recipient gets the data packet. if a cable fails only that device is affected
  17. 17evaluate the ring network topologyAll nodes are connected in a loop
    Each node is connected directly to ring or by spur
    Data passes from node to node till the intended recipient receives it.
    Data travels in one direction
    Less secure as data goes from node to node till intended recipient
    Less reliable as if one cable fails the whole netwok is down
  18. 18PROTOCOLSPROTOCOLS
  19. 19explain the need for communication protocols;.
  20. 20• describe the Open Systems Interconnection (OSI) network organization model and each of its component layers.
  21. 21Describe the Application, Presentation, Session, Transport Network, Data link and physical layers of an osi model.
  22. 22describe the communication protocol Transmission Control Protocol/Internet Protocol (TCP/IP);.
  23. 23describe the communication protocol Ethernet;.
  24. 24describe the communication protocol Carrier Sense Multiple Access with Collision Detection (CSMA/CD);.
  25. 25describe the communication protocol token passing;.
  26. 26describe the communication protocol Wi-Fi;,
  27. 27describe the communication protocol Bluetooth;.
  28. 28describe the communication protocol voice over internet protocol (VoIP).
  29. 29describe the communication protocol radio-frequency identification (RFID)..
  30. 30TRANSMISSION MEDIATRANSMISSION MEDIA
  31. 31Define the term broadband.
  32. 32Define the term Bandwidth.
  33. 33Describe metal cable.
  34. 34Describe fibre optic.
  35. 35Describe Wireless.
  36. 36Evaluate these transmission media in terms of volume of data transfer, bandwidth and security;.
  37. 37DATABASESDATABASES
  38. 38describe the main features of a relational database;.
  39. 39describe the difference between a logical data model and a physical data modelLDM - Produced during the design stage
    It identifies the entities the relationships for each entity the keys for each entity and the attributes for each entity.
    PDM - Produced during implementation. It creates the table column, the column names, the data type of each field, the keys for each table and the validation rules
  40. 40Define the term attributea data item within an entity
  41. 41Define the term EntityAn object of which data is stored
  42. 42Define the term Primary key.
  43. 43Define the term Composite keyConsists of 2 or more data fields which can be a primary key that uniquely identifies an entity occurrence
  44. 44Define the term Foreign key.
  45. 45Define the term RelationshipA link of 2 entities established using a foreign key in one entity to a primary key in another E.g. 1 to 1 1 to many many to many
  46. 46Define the term Referential integrityEnsures data in one table doesn't contradict data in another table e.g. foreign key must relate to a valid primary key
  47. 47Define the term Data duplicationA non key attribute is stored more than once in the database
  48. 48Define the term Data inconsistencyAn attribute for an entity has more than one value
  49. 49describe the characteristics of first normal form (1NF)All attributes are atomic and entities do not have repeating groups
  50. 50Describe the characteristics of second normal form (2NF)The data must be in 1 NF
    aLL repeating groups have been removed and all non-key attributes are dependent on the primary key
  51. 51Describe the characteristics of third normal form (3NF)The data must be in 2nf, There are no partial dependencies, There are no non-key dependancies.
  52. 52describe the advantages and disadvantages of normalisationDatabases take up less space due to not having as much data duplication.
    Databases are more efficient as they are structured more effectively; queries are faster,
    Fewer data redundancies means fewer inconsistencies
    Data integrity will be improved
    Complex process
    Maybe more tables than un-normalized data
    Queries may run slower as there are more tables
    Queries are more complex to create
    Have to assign more relationships
  53. 53What is ER modelling?It uses er diagrams to represent real-world objects and the links between them, it is used in the design stage, it identifies the entities and relationships it's a graphical approach to a database design
  54. 54describe the components of a data dictionaryField name, Field size, Data type, Indexes, Input mask Validation rules, Table name and format
  55. 55evaluate Query By Example (QBE) as an alternative to SQLQBE - A visual way of querying a database, the user inputs data using a wizard to create a query (User Requires minimal technical skill)
    SQL - A programming language that provides a set of commands to create queries (High-level technical skill required-Experienced programmers can create complex queries efficiency-It provides good facilities for creating complex querys
  56. 56ERROR DETECTION AND CORRECTIONERROR DETECTION AND CORRECTION
  57. 57Describe Parity Bits.
  58. 58Describe Check Sums.
  59. 59Describe Echo Checking.
  60. 60Describe CRC (Cyclic Redundancy Check).
  61. 61ARTIFICIAL INTELLIGENCEARTIFICIAL INTELLIGENCE
  62. 62explain what is meant by artificial intelligence (AI);Its the study of all aspects of intelligence and this is modelled by computer systems. The aim is to create intelligent machines which can react and think like humans by learning and adapting.
  63. 63explain the significance of the Turing test in defining what is meant by AI;.
  64. 64Explain neural network modellingModel of the human brain.
    It consists of a collection of nodes linked by 1 way or 2-way connections.
    Each node calculates the weighted sum of its inputs and provides an output
    Propagation may be used
  65. 65EXPERT SYSTEMSEXPERT SYSTEMS
  66. 66describe the structure of an expert system.
  67. 67• describe the purpose of the knowledge base in an expert system;.
  68. 68Describe the purpose of an inference engine.
  69. 69Describe the purpose of the user interfaceThe user will input information, they will answer questions here and get a solution
  70. 70• explain the term Shell in relation to expert systemsSoftware development used to create an expert system.
    It's a skeleton expert system which for a particular application they will add relevent rules and information
    it contains the components of an expert system
  71. 71explain the term heuristics;.
  72. 72Explain the term fuzzy logicIt uses probabilities instead of true/false.
    It can be used with incomplete data
    computers can mimic human reasoning
    Fuzzy logic was created to solve problems by making the best possible decsion given the input
  73. 73Explain the term knowledge engineer;Acquires the knowledge for an expert system through structured and unstructured interviews concept maps etc. It is then put into a database and the knowledge is verified
  74. 74evaluate the use of expert systems in medicine, car engine fault diagnosis and life insurance.Contains the knowledge for a medical/car/life insurance on ect from doctors manufactures ects
    -refects the knowledge of a number of __experts
    -ES Accurate and consistent diagnosis/..
    -It can provide reasonings for diagnosis
    -can capture the knowledge of personnel who are moving to different areas etc
    - can be used as a training aid
    An efficient way of answering quires
    HOWEVER
    - it cannot use intuition
    -Over-reliance on ES can lead to loss of human expertise
    - its Not as good as having a human expert instead
    -Most ES are menu-driven and cant deal with ambiguous problems
    -Cant learn from feedback unless it's a part of the development
    -It's expensive in time and money to create a good expert system
  75. 75NATURAL LANGUAGE AND VOICE RECOGNITIONNATURAL LANGUAGE AND VOICE RECOGNITION
  76. 76describe the technology required for natural languageUsed for Spam filters-identifies sentences used in spam etc.
    Part-of-speech tagging is a self-learning algorithm that tags words with multiple meaning
    Parse trees - It breaks the sentence down into noun and verbs phrases
    Semantics - If a word has multiple meanings then it will tag the words before and after the words e.g board MEMBER, BREAD board
  77. 77describe the technology required for voice recognition systems;A device with a sound card is needed and microphone/headset-mobiles have this inbuilt.
    Pattern matching - words are recognised in their entirety-yes/no
    Pattern and feature analysis - spoken language is digitised using an analogue to digital converter atd and compared to a stored dictionary
    Statistical analysis - uses grammar to predict words (good where words aren't spoken clearly)
    Artificial neural networks - using examples to identify language
  78. 78• evaluate the use of natural language systems;-No training is necessary
    -Makes it more accessible
    -paired VR can leave hands free to do other tasks
    HOWEVER
    -applications can be complex to complete and therefore expensive
    -Commands will not always be recognised correctly
  79. 79• evaluate the use of voice recognition systems;No training required
    -accurate spelling for people with literacy problems
    An accessible way of input
    HOWEVER
    Users may need to speak slower/louder
    May need to train it to peoples voices
    Prone to interference
  80. 80ROBOTICSROBOTICS
  81. 81describe the technology involved in the use of robotics;Computer controlled machines the design functionality etc.
    Controller - Coordinats operation of other parts
    Arm - Positions the end effectors
    End effector - Carries out specific function
    Drive - Moves the parts of the robot into an appropriate position when completing a task
    Sensors - Feeds back to the controller the environment the end effector is interacting with
  82. 82evaluate the use of robotics in a range of commercial situationsSpray painting, surgery, welding, product assembly, aerospace robots
    -Reliable consistant and accurate
    -Can work in hazardous conditions
    -Can preform repetitive tasks withoit making mistakes or getting tired
    -Can work long hours
    -Can be precise(make incisions small)
    -Can be reprogrammed
    HOWEVER
    -Cannot use judgement/intuition, humans can
    -Humans are more flexiable
    -May take time to reprogram
    -Humans need to be trsined to use the robots

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Description
The whole A2 ccea course for digital technology - if I don't forget to upload it lol. Spec from 2017
Created by
Abbie Welch · Jan 2022
Updated
Jan 24, 2022
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196
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