35160739
Description
Flashcards by Abbie Welch, updated more than 1 year ago
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Created by Abbie Welch
almost 3 years ago
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| Question | Answer |
| NETWORKS | NETWORKS |
| What 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 |
| What 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 |
| What 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 |
| describe the purpose of a network card | A 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 |
| describe the purpose of a server | Manages network resources e.g. peripherals, printers etc. and processes requests from other nodes |
| describe the purpose of a switched hub | It 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 |
| describe the purpose of a repeater | It regenerates a data transmission signal which has been attenuated Used over long distances |
| • describe the purpose of a wireless access point | Used to connect a node using wifi/Bluetooth in a hotspot using radio transmitters |
| • describe the purpose of a media converter | It allows 2 dissimilar devices to connect. it changes physical signals from 1 media type to another |
| • describe the purpose of an IP address | It 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 |
| • 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 |
| describe 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 |
| describe the features of a server-based network | A central node controls the network and resources Each node has to request resources from the server Remote software upgrades are possible |
| evaluate the bus network topology | All 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 |
| evaluate the star network topology | All 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 |
| evaluate the ring network topology | All 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 |
| PROTOCOLS | PROTOCOLS |
| explain the need for communication protocols; | . |
| • describe the Open Systems Interconnection (OSI) network organization model and each of its component layers | . |
| Describe the Application, Presentation, Session, Transport Network, Data link and physical layers of an osi model | . |
| describe the communication protocol Transmission Control Protocol/Internet Protocol (TCP/IP); | . |
| describe the communication protocol Ethernet; | . |
| describe the communication protocol Carrier Sense Multiple Access with Collision Detection (CSMA/CD); | . |
| describe the communication protocol token passing; | . |
| describe the communication protocol Wi-Fi; | , |
| describe the communication protocol Bluetooth; | . |
| describe the communication protocol voice over internet protocol (VoIP) | . |
| describe the communication protocol radio-frequency identification (RFID) | .. |
| TRANSMISSION MEDIA | TRANSMISSION MEDIA |
| Define the term broadband | . |
| Define the term Bandwidth | . |
| Describe metal cable | . |
| Describe fibre optic | . |
| Describe Wireless | . |
| Evaluate these transmission media in terms of volume of data transfer, bandwidth and security; | . |
| DATABASES | DATABASES |
| describe the main features of a relational database; | . |
| describe the difference between a logical data model and a physical data model | LDM - 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 |
| Define the term attribute | a data item within an entity |
| Define the term Entity | An object of which data is stored |
| Define the term Primary key | . |
| Define the term Composite key | Consists of 2 or more data fields which can be a primary key that uniquely identifies an entity occurrence |
| Define the term Foreign key | . |
| Define the term Relationship | A 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 |
| Define the term Referential integrity | Ensures data in one table doesn't contradict data in another table e.g. foreign key must relate to a valid primary key |
| Define the term Data duplication | A non key attribute is stored more than once in the database |
| Define the term Data inconsistency | An attribute for an entity has more than one value |
| describe the characteristics of first normal form (1NF) | All attributes are atomic and entities do not have repeating groups |
| Describe 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 |
| Describe the characteristics of third normal form (3NF) | The data must be in 2nf, There are no partial dependencies, There are no non-key dependancies. |
| describe the advantages and disadvantages of normalisation | Databases 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 |
| What 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 |
| describe the components of a data dictionary | Field name, Field size, Data type, Indexes, Input mask Validation rules, Table name and format |
| evaluate Query By Example (QBE) as an alternative to SQL | QBE - 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 |
| ERROR DETECTION AND CORRECTION | ERROR DETECTION AND CORRECTION |
| Describe Parity Bits | . |
| Describe Check Sums | . |
| Describe Echo Checking | . |
| Describe CRC (Cyclic Redundancy Check) | . |
| ARTIFICIAL INTELLIGENCE | ARTIFICIAL INTELLIGENCE |
| explain 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. |
| explain the significance of the Turing test in defining what is meant by AI; | . |
| Explain neural network modelling | Model 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 |
| EXPERT SYSTEMS | EXPERT SYSTEMS |
| describe the structure of an expert system | . |
| • describe the purpose of the knowledge base in an expert system; | . |
| Describe the purpose of an inference engine | . |
| Describe the purpose of the user interface | The user will input information, they will answer questions here and get a solution |
| • explain the term Shell in relation to expert systems | Software 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 |
| explain the term heuristics; | . |
| Explain the term fuzzy logic | It 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 |
| Explain 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 |
| evaluate 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 |
| NATURAL LANGUAGE AND VOICE RECOGNITION | NATURAL LANGUAGE AND VOICE RECOGNITION |
| describe the technology required for natural language | Used 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 |
| describe 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 |
| • 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 |
| • 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 |
| ROBOTICS | ROBOTICS |
| describe 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 |
| evaluate the use of robotics in a range of commercial situations | Spray 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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