I decided I would attempt the blog as I haven’t in a while. Today we were learning more about expert systems.

Basically an expert system is a program that contains the specialist knowledge of one or more experts.

• They are used to solve problems.
• They provide the user with advice and can explain that advice, and particular questions.
• They must be able to handle uncertain and incomplete information.

You will need to know all of the following for the exam…

-3 component parts of an expert system

• Knowledge base, which is based on rules and facts.
• User interface, which requests information from the user and outputs immediate and final results.
• Inference engine, which applies facts to rules and determines the order of questions asked.

-4 categories of expert systems

• Advice/advise
• Diagnosis
• Classification e.g. gender identifier/animal identifier
• Planning

-Creating production rules

• IF commands
• IF, AND, (IS, ARE, =) THEN which are keywords
• Must be done in a specific way

KEY WORDS MUST BE IN CAPITALS OR YOU WILL NOT GET IT MARKED CORRECT!!

-Stages in developing expert systems

• Knowledge acquisition – you have to find the required expert and speak to them; continual updating.
• Knowledge representation
• System validation

-Justification facilities of and expert system

• How
• Why

Today we also did a kind of programming thing on the computer, which involved us making toast (not literally). It was a basic programming programme where we used ‘backward rule’, and previously we used ‘forward rule’. These programs ask us particular questions and depending on our answer, it gives us advice and ends with hopefully giving us a solution best suited to what we want to do. Once you have so many parts to your program it may skip to for example question 3 and ask it, and only ask you questions 1 and 2 if your answer was ‘no’ to question 3. e.g. the first question may say ‘is toaster switched on?’ and second may say ‘is the toaster plugged in?’ and the third may say ‘is grill used?’ so unless you said no to the grill being used it would ask about the toaster, as you must of made your toast in the toaster. The program gets more complex by adding questions about spreading butter and jam etc.

This activity was good, excluding the fact that I got disqualified as I was ‘’cheeky’’ which I clearly wasn’t, i was just giving my view on what way round the questions should be asked, surely you are allowed your own say on things!

Ok, that’s me done i think, don’t have a clue if it will help anyone as i’ve probably talked a lot of rubbish but hey ho!

Crumblebum

Jerome has asked me to blog about relaxing music too put together a playlist for class.  He wants too know what song everyone listens too the most when studying that helps them relax?

He will then buy these and play them in class

Comment this blog with your fav song please!!!

Michael

P.s mines is     ‘Just For Tonight’  by  ’One Night Only’

Today in info systems we learned about Backup strategies
Companies with a significant amount of data stored should have a robust backup system, to keep data loss impact to a minimum.

Things to consider when choosing a strategy are:

• What storage media will be used for the backups
• Which data is to be backed up
• When backups should take place
• Where data should be stored

The grandfather father son methodology

If we consider a system where backups are taken each Friday on magnetic tape, then daily incremental backups (where only new information is backed up) take place from Monday until Thursday. On a Friday however, all files will be backed up regardless of whether they have changed or not. In this case, the backup runs automatically at 10pm. On the last working day of each month there is a full back up on to a first monthly tap. This schedule can be used quarterly throughout the year before monthly tapes are re-used.

The daily backups, containing the least amount of data and the newest data, are known as the son files.
The weekly backups contain a greater volume of data. These are the father files.
The monthly backups contain the oldest data so are known as the grandfather files.

Recovering data

To recover data using this strategy would require using the most recent weekly tape and each of the daily tapes from when the data failure took place.

For example: If there was a complete data failure on Thursday in week 3, we would require the files from Monday to Wednesday in week 3

Rotating data

In the event of a disaster such as a fire or theft, extra media could be used and stored off-site. A fire safe should be used to safely store the tapes that are kept on-site.

To be honest I didn’t expect anyone to read down this far, but if you have, well done, you have read my first attempt at the blog.

I will begin with the hardware required, this may make it easier to understand when I start to describe the topologies.

Node - A physical network node is an active electronic device that is attached to a network, and is capable of sending, receiving, or forwarding information. For example, a computer, a printer, hub, switch.

Ethernet - The ethernet protocol is by far the most widely used. Ethernet uses an access method called CSMA/CD (If you remember this is the phrase Mr.McGivern wanted us to revise and learn), it stands for Carrier Sense Multiple Access / Collision Detection. This is a system where each computer ‘listens’ to the cable before sending anything through the network. If the network is clear, the computer will transmit. If another node is already transmitting on the cable, the computer will wait and try again when the line is clear. Sometimes, two computers attempt to transmit at the same time. When this happens a collision occurs. Each computer then backs off and waits a random amount of time before attempting to re-transmit.

Hub - Hubs are commonly used to connect segments of a network. A hub contains multiple ports. They are usually connect to other nodes, through a ethernet cable. When a block of data (a packet) arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets. Hubs repeat everything they receive and can be used to extend the network. However, this can result in a lot of unnecessary traffic being sent to all devices on the network.

Switch - A switch acts very much as a hub, however a switch can interpret the destination of data packets and will route packets only to their intended destination. This increases the capacity of the network because the incoming data is not repeated to every node. A switch also has a lot more ports than a hub, meaning more computers can be connected to the network.

Router - Route-r for Michael , Is a device which forwards data packets along networks. It is normally connected to at least two networks, often two LANs or WANs or a LAN and an internet service provider’s network. Routers are located at gateways, the places where two or more networks connect.

So with the hardware cleared up, I will now move onto the topologies. After at least all of us got hired and fired by Mcgivern as his network manager, we did get to the bottom of the topologies and what each network consists of.

Star Topology

A star topology is designed with each node connected directly to a central node. The central node can be a network hub or switch. The central node offers a common connection for all nodes on the network. Each network device has its own direct cable connection to the central node. In most cases, this means more cable is required than a bus topology. However, this makes adding or moving computers a relatively easy task: simply plug them into a cable outlet on the wall.

Advantages of a Star Topology

∙ It is relatively easy to install and wire a star network because the construction of the network only revolves running a cable from each network device to the central node.

∙ It is easy to detect faults and to remove parts because if an error occurs it should only affect one node on the network, therefore making fault finding easier.

Disadvantages of a Star Topology

∙Significantly more network cabling must be used to create a star network in comparison with a bus network.

∙If the central node fails, all other nodes attached to it are disabled and unable to communicate with any other node on the network.

∙Star networks are more expensive than bus topologies because of the cost of the hub or switch that is needed to function as the central node.

Tree Topology

A tree topology is like a series of interconnected star topology networks. Tree Topologies allow for the expansion of an existing network, and enable organisations to configure new networking to meet their needs.

Advantages of a Tree Topology

∙ Additional nodes can be added easily to individual segments, and segments can be added easily to the main central node.

∙ It is relatively easy to install and wire a tree network. Construction of the network involves simply running a cable from each network device to the central node in each segment, and then connecting the segments.

∙ Each device on the network has its own connection to the central node in the segment, and therefore there are no disruptions to the network when connecting or removing devices.

∙ It is relatively easy to detect faults and to remove parts. This is because if an error occurs it should only affect one node or segment on the network.

Disadvantages of a Tree Topology

∙The overall length of each segment is limited by the type of cabling used. If the central node fails the network fails.

∙Overall, the tree topology is more difficult to configure and wire than other topologies.

Ring Topology

A ring topology consists of a set of nodes connected serially by cable. In other words, it is a circle or ring of computers. There are no terminated end to the cable; the signal travels around the circle in a clockwise direction.

Under the ring concept, a signal is transferred sequentially via a `token’ from one station to the next. When a station wants to transmit, it `grabs’ the token, attaches data and an address to it, and then sends it around the ring.

Advantages of a Ring Topology

∙Networks based on a ring topology can grow without significantly impacting on the performance of the system.

∙All stations on the network have equal access to communication because of the use of the token.

Disadvantages of a Ring Topology

∙Ring networks require specialist hardware to function which makes them one of the most expensive topologies to implement.

∙It is possible that the failure of one computer may impact on others in a clockwise direction around the ring.

Mesh Topology

Mesh is a network topology in which devices are connected with many redundant interconnections between network nodes. In a true mesh topology every node has a connection to every node in the network; this is called a fully connected mesh. In a partially connected mesh, there are still multiple connections but all nodes are not connected.

Advantages of a Mesh Topology

∙ Mesh topologies provide multiple physical paths along which data can travel. If one of the network connections is cut there will normally be another route available along which can travel to reach its destination.

Disadvantages of a Mesh Topology

∙Mesh topologies are expensive to implement because of the multiple physical connections required to link each node on the network. These physical connections are difficult to install because of the sheer number involved.

∙The complexity of the mesh makes it difficult to manage. Keeping track of the network data cables and their connections and routes becomes a very difficult task with such a complicated network.

∙If an error occurs it can be difficult to detect, five the sheer number of network cables involved.

I know that is alot to take in, but it took me 10x as long to do as it will for you to read it.

Hope it was of help to you !
Ryan Jardine

Orrrrr a Mintedddd.

I will begin with the hardware required, this may make it easier to understand when I start to describe the topologies.

Node - A physical network node is an active electronic device that is attached to a network, and is capable of sending, receiving, or forwarding information. For example, a computer, a printer, hub, switch.

Ethernet – The ethernet protocol is by far the most widely used. Ethernet uses an access method called CSMA/CD (If you remember this is the phrase Mr.McGivern wanted us to revise and learn), it stands for Carrier Sense Multiple Access / Collision Detection. This is a system where each computer ‘listens’ to the cable before sending anything through the network. If the network is clear, the computer will transmit. If another node is already transmitting on the cable, the computer will wait and try again when the line is clear. Sometimes, two computers attempt to transmit at the same time. When this happens a collision occurs. Each computer then backs off and waits a random amount of time before attempting to re-transmit.

Hub - Hubs are commonly used to connect segments of a network. A hub contains multiple ports. They are usually connect to other nodes, through a ethernet cable. When a block of data (a packet) arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets. Hubs repeat everything they receive and can be used to extend the network. However, this can result in a lot of unnecessary traffic being sent to all devices on the network.

Switch – A switch acts very much as a hub, however a switch can interpret the destination of data packets and will route packets only to their intended destination. This increases the capacity of the network because the incoming data is not repeated to every node. A switch also has a lot more ports than a hub, meaning more computers can be connected to the network.

Router - Route-r for Michael , Is a device which forwards data packets along networks. It is normally connected to at least two networks, often two LANs or WANs or a LAN and an internet service provider’s network. Routers are located at gateways, the places where two or more networks connect.

So with the hardware cleared up, I will now move onto the topologies. After at least all of us got hired and fired by Mcgivern as his network manager, we did get to the bottom of the topologies and what each network consists of.

Star Topology

A star topology is designed with each node connected directly to a central node. The central node can be a network hub or switch. The central node offers a common connection for all nodes on the network. Each network device has its own direct cable connection to the central node. In most cases, this means more cable is required than a bus topology. However, this makes adding or moving computers a relatively easy task: simply plug them into a cable outlet on the wall.

Advantages of a Star Topology

∙ It is relatively easy to install and wire a star network because the construction of the network only revolves running a cable from each network device to the central node.

∙ It is easy to detect faults and to remove parts because if an error occurs it should only affect one node on the network, therefore making fault finding easier.

Disadvantages of a Star Topology

∙Significantly more network cabling must be used to create a star network in comparison with a bus network.

∙If the central node fails, all other nodes attached to it are disabled and unable to communicate with any other node on the network.

∙Star networks are more expensive than bus topologies because of the cost of the hub or switch that is needed to function as the central node.

Tree Topology

A tree topology is like a series of interconnected star topology networks. Tree Topologies allow for the expansion of an existing network, and enable organisations to configure new networking to meet their needs.

Advantages of a Tree Topology

∙ Additional nodes can be added easily to individual segments, and segments can be added easily to the main central node.

∙ It is relatively easy to install and wire a tree network. Construction of the network involves simply running a cable from each network device to the central node in each segment, and then connecting the segments.

∙ Each device on the network has its own connection to the central node in the segment, and therefore there are no disruptions to the network when connecting or removing devices.

∙ It is relatively easy to detect faults and to remove parts. This is because if an error occurs it should only affect one node or segment on the network.

Disadvantages of a Tree Topology

∙The overall length of each segment is limited by the type of cabling used. If the central node fails the network fails.

∙Overall, the tree topology is more difficult to configure and wire than other topologies.

Hub/Switch





Ring Topology

A ring topology consists of a set of nodes connected serially by cable. In other words, it is a circle or ring of computers. There are no terminated end to the cable; the signal travels around the circle in a clockwise direction.

Under the ring concept, a signal is transferred sequentially via a `token’ from one station to the next. When a station wants to transmit, it `grabs’ the token, attaches data and an address to it, and then sends it around the ring.

Advantages of a Ring Topology

∙Networks based on a ring topology can grow without significantly impacting on the performance of the system.

∙All stations on the network have equal access to communication because of the use of the token.

Disadvantages of a Ring Topology

∙Ring networks require specialist hardware to function which makes them one of the most expensive topologies to implement.

∙It is possible that the failure of one computer may impact on others in a clockwise direction around the ring.

Mesh Topology

Mesh is a network topology in which devices are connected with many redundant interconnections between network nodes. In a true mesh topology every node has a connection to every node in the network; this is called a fully connected mesh. In a partially connected mesh, there are still multiple connections but all nodes are not connected.

Advantages of a Mesh Topology

∙ Mesh topologies provide multiple physical paths along which data can travel. If one of the network connections is cut there will normally be another route available along which can travel to reach its destination.

Disadvantages of a Mesh Topology

∙Mesh topologies are expensive to implement because of the multiple physical connections required to link each node on the network. These physical connections are difficult to install because of the sheer number involved.

∙The complexity of the mesh makes it difficult to manage. Keeping track of the network data cables and their connections and routes becomes a very difficult task with such a complicated network.

∙If an error occurs it can be difficult to detect, five the sheer number of network cables involved.

There are five key areas which organisations must consider as part of the development and operation of organistional information systems. These are:

• network strategy
• security strategy
• backup strategy
• upgrade strategy
• software strategy

Since we’ve only looked at Network strategy, I will begin there.

Basically a network strategy allows an organisation to manage how data is distributed across the enterprise. It’s necessary for an organisation to function correctly.

There are different types of network, there’s a chance we can be asked about these in the exam so it’s worth learning it.

• local-area networks (LANs) : This is where the computers are in close proximity (that is, in the same building).
• wide-area networks (WANs) : The computers are farther apart and connected by telephone lines or radio waves.
• campus-area networks (CANs) : The computers are within a limited geographical area like a campus etc.
• metropolitan-area networks (MANs) : A data network designed for a town or city.
• home-area networks (HANs) : A network contained within a user’s home that connects media devices, computers and network enabled domestic appliances.
  

The most common of these are LANs and WANs.

Topology

A topology is the physical structure of the network, how the workstations are connected by cable.

The first topology we have looked at is the bus topology. It consists of a main run of cable with a terminator at each end. All the network devices (nodes) are connected to the cable.

 Advantages of a bus topology

• It’s easy to implement and extend because all that is needed is a back-bone cable into which the various nodes are attached.
• They’re well suited for temporary networks that must be set up in a hurry and where costs are to be kept to a minimum.
• If one node fails then the network doesn’t fail because the data flows along the bus rather than the individual nodes.

Disadvantages of a bus topology

• The entire network shuts down if there is a break in the back-bone cable.
• They require terminators at both ends of the back-bone cable to indicate the physical end of the network. They absorb the the signals so that they don’t bounce back and interfere with network traffic.
• If the network does have a failure then it’s very difficult to pin point the problem. Sometimes the only way to locate the problem is to move the terminator along the bus, shortening the length of the network until it functions again.

Because of these disadvantages bus topologies are not meant to be used in large building or complexes.

If in an exam you’re asked to describe a bus topology (or any other topology), then it’s a good idea to make a small simplified diagram of the topology with the key parts labelled.

Have I missed anything important out?

Relevance- is how appropriate the information is

Accuracy- is  how correct the information is

Completeness- is if you have all the information

Reliability - is how trustworthy the information is

Timing - is how up-to-date the information is

Level of detail – is the amount of information there is

Presentation - is the way the information is displayed

Availability – how easy it is to access information/ how readily available it is

Value -  how importance the information is to you

 Cost -the price that  information costs

We then moved onto Organisational Information Systems, which are information systems used by organisations. For example, a computerised database used by B&Q to monitor item sales.

Different systems are used at different levels of management

Data Processing Systems

• Used by the Operational Level
• Used generally to process numerical data
• Produce significant amounts of data on a daily basis both input and output
• Critical in day to day functioning of an organisation
• Used for example in supermarket tills

Decision Support System

•  Used at the tactical level of management
• used to retrieve, summarise and analyse data
• this then helps managers to make decisions
• Helps with “what if” analysis

Management Information Systems

• Also used at tactical level
• Uses a large amount of input data e.g. taken from data processing systems
• Helps in decision making or planning
• Draws on internal or external sources of information
• Gives summarised output
• Converts data into information

Exectutive Information System

• Used at the strategic level mangement
• Used to support strategic level decisions
• Summarises data from other information systems
• Drills down to levels below
• Produces summarised information in a graphical format
• Contains the tools to allow forecasting
• Very expensive to set up and maintain due to the level of personal configuration involved.

This is only a summary of the Organisational information system, there are more detailed descriptions in the textbook.

Emma :)

There are eight categories of information:

1. Source
2. Nature
3. Level
4. Time
5. Form
6. Use
7. Frequency
8. Type

So let’s start with number one on the list:

Source - Where the information comes from.

There are four different types of source but I find it easier to think as it of two separate couples of sources. Internal/External sources and Primary/Secondary sources.

Internal Source- Information within an organisation or establishment which the information concerns e.g stroke index of each hole on a golf course which compare it’s difficulty to that of the other holes.  This is worked out by averaging player’s scores over each hole over a span of time.

External Source- Information which originates from outwith the organisation it concerns e.g handicaps of golfers from other golf clubs competing in competitions.

Primary Source- Information comes directly from situation e.g referee’s report after football match.

Secondary source- Passed on from a primary source e.g minutes at a meeting.

Now let’s draw a line under that

—————————————————————————————————————————————————

Nature-   Is this information formal or informal or qualitative or quantitative.

Formal- The information comes from an official source. It would be verified so would be reliable and accurate e.g a letter from a company informing someone of success in an application of some sort.

Informal- Information would come from a less authoritative source and would be less formally presented e.g a casual e-mail

Qualitative- Information mainly based on perceptions, evaluations and opinions e.g the view of delegates on a convention venue

Quantitative- Information which consists of hard facts and is recorded using formal methods e.g a tourist board for an area could count the number of tourists from adding up hotel bookings.

—————————————————————————————————————————————————

Level- Is information strategic, tactical or operational

Strategic- Information at this level is used by senior managers and often consists of summary information and forecasts.  It is used for major planning issues and is often considered for plans over a number of years e.g Iceland in Johnstone see’s a 70% increase in customers so the executives of the whole Iceland company decides to open a new store in Johnstone within the next three years to meet the demand.

Tactical- Information used by middle managers to plan for the medium term e.g the manager of Iceland in  Johnstone decides to employ more staff to cope with the upsurge in demand

Operational -Information used in the day-to day running of an organisation e.g person in charge of ordering stock  may increase orders for ice-cream in the summer and reduce it in the winter

—————————————————————————————————————————————————

Time- Does this information refer to the past, present or future?

Historic- Information is gathered over time and is mainly used in order to identify trends e.g sun cream sales in July over the last 10 years in order to determine production

Present- Information is current for the period indicated e.g a school timetable

Future- Information which predicts what may happen in the future. Information is based upon both historic and present information e.g determining what will happen to house prices

—————————————————————————————————————————————————

Form- How the information is presented

Written- Information is written down includes reports, tables of data and may require a code or laguage for understanding e.g an order of goods from a warehouse will be listed as codes found in a catalogue.

Aural – Information which can be heard e.g a voicemail message on a phone

Visual- Information that can be seen e.g graphics, pictures or video footage

NOTE- Some things can show all 3 of these forms e.g  a Powerpoint presentation

—————————————————————————————————————————————————

Use- What is the purpose of the information

Control- Information is used to monitor and give feedback on the situation to which the information relates. The feedback can be used to change actions.  This can be done at any level.

Decision making- Again used at all levels and is taking action on available information e.g the re-stocking of an empty shelf in a shop

Planning- The use of information to make plans about the future use of resources at any level e.g scheduling production in a factory

————————————————————————————————————————————————–

Frequency- How often is this information updated?

Continuous- Information is updated and available as it is generated.  Also known as real-time e.g results for NAB  was being marked while being answered

Periodic- Information becomes available over regular time intervals e.g daily absence report

Random- No predetermined structure to time period as information is gathered randomly e.g booking flights on-line

—————————————————————————————————————————————————

Type – Is information detailed, statistical or summarised?

Detailed- Detail of information increases as the level rises e.g teacher would know exact score in test whereas head would only know grade.

Aggregated – Information is combined and summarised

Sampled- Only some information is used e.g obtaining viewing figures for a TV show only a small proportion of TV viewers are consulted

————————————————————————————————————————————————–

And there we have it done.

Goodbye

Scott Edgar

How does everyone find them? Who finds them useful? What are you really looking from them?

In my opinion sometimes they are ok other times I get more confused.

Recently in class we started our second topic in Information Systems, and because of the amount we have done I’m not too sure about what’s really happening yet so don’t have a clue what to write about

Our second topic is Using Information

In the good words of Mr Mcg this topic is “a beast.” Doesn’t sound too healthy to say the least but hopefully I can help with the first few parts in this blog.

The first few questions we were asked in this new subject were questions just about all of us knew the answers to but never really knew how to word them. However, if Mr Mcg talks the truth we need to be aware of this problem often in this topic, so be prepared.

“What is data” – Mr Mcgivern

Seems a simple question but how to word it, makesd this a question harder than it really is. Reading the book will give you a simple explanation but back with the teacher’s words,

“Data refers to raw facts/figures without meaning or context.” An example of data is 0 4 . What does it mean? Having to ask that question proves it is data and more is needed to know to find out.

Secondly we were asked “What is information”

Probably two of the easiest questions we will get to start a topic in any subject but, how do we answer again.

Information is data which has been given a meaning and context. Continuing my example from above our 0 4 can be turned into celtic 0 – 4 rangers.

Know you know what the first 0-4 is actually about.

And to finish these key terms questions we were asked “What is knowledge”

Knowledge is information which you understand. This is found from using your information. Again with using the above example we can see that on the day rangers were better than celtic.

Now you can see why this is needed, who knew what 0 4 meant it could mean anything so these parts were needed.

Next thing we went to look at was

Categorisation of information

This involves eight parts and can be easily remember with this simple saying,

Some Nuts Love To Frequently Use Form Tables

If you cant remember that then make up your own and blog it to see if you can help others.

The above saying stands for the eight parts involved in the categorisation of information. Below I will list them and list what is involved in them.

Source – External/Internal/Primary/Secondary

Nature – Formal/Informal/Quantitative/Qualitative

Level – Strategic/Tactical/Operational

Time – Hitory/Present/Future

Form – Written/Aural/Visual

Use – Planning/Control/Decision making

Frequency – Continuous/Periodic/Random

Type – Detailed/ Sampled/Aggregated

We went into detail on most of these and were given examples however I can’t blog these as I did not get enough notes and don’t want to make mistakes and cause problems. I appologise for any problems

Just before we did some questions we were shown

Information Characteristics

However we only touched on these and were not told what they involved,

Relevance, Accuracy, Completeness, Reliability, Timing, Level of detail, Presentation, Availability, Value and Cost.

To finally finish my blog I would like to mention a great find. Personal brain. If anything I have wrote above has helped(which I highly doubt) then put it in there. It may be important at the end of the day and if you put it there it is simple to find and will always be there.

Hopefully this helps a little bit if it doesn’t I’m sorry as that was all the notes i have for our new topic.

Jimjimjambob