Ipt_Study

Study: • Module 1: Project Management • Module 2: Information Systems and Databases • Module 3: Communication Systems • Elective 1: Transactions Processing Systems • Elective 2: Multimedia Module 1: Project Management • Project management is the use of knowledge, skills, tools and techniques to meet the requirements of a project. • Developing a project plan has to start with problem definition. All subsequent steps stem from the project definition. • Once the problem is defined, there a list of requirements that determine the objectives of the plan. • During the design and at the end this list is the basis for evaluation. • Project plan shows structure of any project with a time schedulable, showing dates to start and finish each tasks as well as the overall time frame. • Participants in project plan depends on the size of the plan and the budget. E.g. system analyst, project leader, designer, user. • Communication skills, negotiation skills, active listening. • Ethics: social and ethical design. Projects are unethical if they are racist, violent or break the law. • Machine centred; simplify the task of machines at the expense of humans involved in the system. Human centred: has a human focus and the machine is subservient to human needs. • The environment is not part of the system but is an aspect that affects it in some way. • Prototypes are working models of an information system and are a method of assisting further understanding of any problem. • Prototypes demonstrate the system from the users perspective. • The prototype creation is a repetitive process because it involves creating, showing participants, inviting suggestions and modifying the prototype to produce the next version of the modal until the modal meets the needs of said system. • Feasibility studies are undertaken to determine if a proposed solution is possible. • Economic feasibility. Is it worth the money' • Technical feasibility. Are the resources worthy' • Operational feasibility. How well will the solution work' • Schedule feasibility. Can it be solved in a reasonable time frame' • Participant development involves solving a problem with people within the information system. • Participants design solutions that could modify system development cycle using tools in an application package, following guided processes. • Design tools are tools to help someone design something. • Context diagram, we know what that is. Fucking ugly poo shit. • We know what a data flow diagram is. Skip that motherfucker. • Decisions table: describes a process within the information system. Shows a series of guidelines and columns that one uses as a set of rules. • We know what a data dictionary is. • We know what a systems flow chart is. • Implementing is the process of carrying out the project plan. • Implementation should involve training undertaken by participants. • Determining the method of conversion deciding the testing methods to determine if the new system fulfils the specifications. • Fucking hell. • Operators – participants who will use the system daily. • Users – managers and others who need info in order to base decisions. • System managers – those responsible for assisting and training others in the use of the system. • Parallel conversion, phased conversion, direct conversion and pilot conversion. Module 2: Information Systems and databases • An information system is an arrangement of components integrated to fulfil the needs of people. The output is information. • Data is raw facts from which information is obtained within the system and it can be seen on two levels which is: actual facts related to the system and metadata (data describing data in the system. • Organisation is the structure of data. Without this data is meaningless. Data can be organised through sorting, indexing, summarising, listing etc. • Analysing is extraction of specific information from the data such as reporting and synthesising. • Types of info systems: Transaction Processing System, Decision Support System, Management Information System, Office Automation System. • A database is any organised collection of data stored and retrieved to meet the needs of multiple users. Data is the most critical part of the database. • Database information systems must have boundaries like all information systems. Without boundaries databases would be impossible to control due to too much data. • Storage = storage of data/ Retrieval = retrieving of data. Processing = manipulation and analysis of data. Networking = data access from multiple sites. • Data base management system DBMS is a utility providing many services for a large database. • Hypermedia is the term used to describe the combination of media containing information organised in such a way that it is possible to navigate between components of information irrespective of the particular medium that information is stored. • Flat File Database is a database in which data is stored and retrieved from one table. • Keys are fields in a database that allow data to be accessed. A single key is any field in the database in which each item of data held in the field is unique. The composite key is a group of two or more fields use to identify a field or record within a database. A primary key is a character or group of characters used to identify unique records in a database. Secondary key is a field or combinations of fields that aren’t exactly unique to a record but apply to one or more records. • Schematic diagrams display a model of the database design to show a relationship between entities. • An entity is anything specific about which data has to be recorded. • Entity relation relationship diagram is one type of schematic diagram. • Normalising data, Normal forms are rules aimed at eliminating redundancy in data. • Breaking down the amount of information in a single database into smaller ones and relating them all together. Relational databases. • Initial normal form divides the fields into separate tables and gives each table a primary key. • Domain key normal form establishes common ground between the tables so they can be related. • We know direct and sequential access. • Distributed database is a database stored on computers at several sites. • Encryption is coding data to render data unreadable and decryption is the reverse. • Asymmetric key is where two keys are set up the public: available on a wide scale and private: restricted to those authorised to have it. • Symmetric encryption uses one key for both encryption and decryption. • Sorting A-Z 0-9. • Searching – a query. A question asked to attain data. • Query by example QBE can be used by participants with no formal programming training to get information they need from the database. • Structured query language SQL is a method of formulating queries to retrieve data. And/ or/ greater/ bigger than' • Report is just presentation of data. • Data integrity describe the reliability of data. • Data security is a main issue relating to information systems. • Hacking is a deliberate attempt to source data from a secured source. • Cracking is the term used to describe the hacking of data with criminal intent. • Data warehouse is a collection centre for data. • Data mining is a process where customer databases could be mined to determine relationships between customers and the products they purchase • Data – Fields – Record – Table – Database – File – DBMS • SELECT FROM WHERE ORDER BY • SELECT Contacts* FROM Contacts WHERE Name – Ethan ORDER BE: Name ASC • * = a wildcard which means all the fields • OLAP – Online analytical processing is an approach to swiftly answer multi-dimensional analytical queries. • RFID - Radio-frequency identification is the use of an object applied to or incorporated into a product, animal or person for the purpose of identification using radio waves. • OLTP – Online transaction processing, refers to a class of systems that facilitate and manage transaction-oriented applications, typically for data entry and retrieval transaction processing. Module 3: Communication Systems • Transmitter is hardware encoding data for suitable transmission. • Transmission medium is the mean by which data is sent. • The receiver is the decoder who transforms the data back into its original form. • The destination is the location to where the data is sent. • Protocols are a set of rules that govern the transmission of data. • Most communication protocols follow international set of standards. One such modal is the OSI modal which is open system interconnection modal. • Physical – transfer of electrical signals. Controls physical shit. • Data-link concerned with rules of data and establishes link from source to destination. • Network layer – controls the communication procedures such as how groups of data or packets are routed. • Transport layer – insures that all data correctly arrives at the destination. • Presentation layer – establishes protocols or rules on how data will be represented. Also controls compression methods and encryption. • Application layer – controls the transferring of files and manages the transfer. • Handshaking is defined as the exchange of information as prearranged signal defining a protocol between two computers. • Session level opens the handshaking with a query about the readiness of the receiver. “Hi are you ready over there' Yes I am. What are we going to do today'” • Transmission speed is the time taken to transport data from source to destination • Bandwidth is the measure of the amount of data transferred at a given time. • Bps – bits per second. • Baud rate is used to measure speed in a transmission medium. Measure the number of times per second the medium can change its state. • Error checking methods: parity is the method used to check data where one character is checked at a time. Seven bits are used for each ASCii character with the eighth bit in the bite used to check for error. This is called the parity bit. The parity bit can be either zero or one. When set to even parity a valid character must consist of an even number of bits set to one. Set to odd parity means that a valid character must consists of an odd number of bits set to one. Parity checking works when there is an odd number of errors per character. • Checksum is a series of binary or hexadecimal digits. If the one digits are added they give a total which is the checksum. The receiver computer calculates the checksum then compares it to the transmitted checksum and if there is not a match an error has been encounted. • Cyclic Redundancy Check CRC. Similar to checksum each bit of binary or decimal is treaded as one rather than as separate sums for each packet. • Dealing with errors is just retransmission. • Forward checking works out the redundant data sent with a message that allows it to be reconstructed in an error occurs but this could increase the size greatly. • Symbol substitution doesn’t correct the problem buts puts a symbol where the error is so it is easy to determine what the correct message should have been. Not useful for numbers. • Communication settings are parameters. They can be set automatically when installing communication software. E.g. a modem. • Teleconferencing, email, voice mail. • EFTPOS. Electronic Funds Transfer at Point Of Sale • Parallel transmission. A number of data bits are transmitted simultaneously. Each bit along a separate channel or wire. • Serial transmission. Where the bits are transmitted sequentially one at a time over one channel. • Asynchronous transmission is the transmission of data independent of a time code. • Synchronous transmission is the system of high speed data transmission in which clocks in both recieving and transmitting terminals are sued to determine both data is processed at the same rate. • Simplex mode is a mode of communication between devices allowing transmission in one direction. • Half-duplex mode is a mode of communication between devices allowing the transmission in both directions but not simultaneously. • Full-duplex allows transmission in both directions at the same time. • Nodes are devices attached to the network. • LAN. • WAN provides communication beyond a single site. • Networks can be arranged in many different ways known as topologies. • Star topology – one node coordinates distant nodes. Any messages must pass through this central computer. • Bus network – is where several devices are connected to a signal communications channel. The devices are in a straight line. • Ring network – a continuous circle of nodes. It’s fast and used on large networks. • In token ring the token in constantly travelling around the network and only in one direction. The token is permission to speak. • Bridge connects two LANs together. • Switches connect small sections of LANs. • Routers direct data traffic. • Hubs allow for a single network point to be expanded into multiple network points. • Gateways provide the ability for one protocol to talk to a different one. • Firewalls are hardware or software used to protect the internet, extranet and intranet from external unwanted forces. • Extranet is a private network using internet protocols and communication structures to secularly share part of an organisations operation to those outside but relate it to the organisation. Elective 1: Transaction Processing Systems Elective 2: Multimedia • Media types include but are not limited to: text, hypertext, images/ graphics, video/ animation, sound/ audio. • Animation: a sequence of graphics moving so as to appear to be moving. • Sound and audio – uncompressed, lossy compression and lossless compression. • How are different formats of media saved on a hard drive' • Hard drives are composed of platters or discs. • ASCii is saved as 8 bits • Capitals have different ASCii codes to lowercase • Each number is also 8 bits • Composite numbers are stored in 8 bits • Analogue to digital conversion • A number of different digital snapshots are taken of the analogue waveform each second. This is called sampling. CD quality is 44,100 samples per second with each sample being 16 bits. Stereo would be 40 MB and mono would be 20 MB. DVD is 24 bit. • Compression works by ignoring and removing superfluous information such as the absolute pitch and discernable noise. This is lossy compression. • Lossy compression reduces the original file to one tenth its original size. • Lossless reduces only by a small amount. 40 MB would be more approx 39 MB. • Video works roughly the same. The file size is compressed even further. • Bitmap – 500 by 500 – 500 columns by 500 rows. 250000 pixels. Each pixel is saved in 16 bits. To compress the file only the coloured pixels are recorded. All the white pixels are disregarded. • Animation is pictures or frames moving sequentially in front of each other. • Interactivity: is human interaction to software or an application. • A vector graphic will recognise certain objects such as straight line and circles. This is how this picture will be represented. • Bitmap applies a digital value to every pixel. • OCR – Optical character recognition. • TWAIN – Technology without an interesting name. • Sound card – MIDI – Musical Instrument Digital Interface • Converging technology is using a computer to do a number of different tasks. Listening to radio online. • CRT: Cathode Ray Tube. A vacuum tube containing an electron gun (a source of electrons) and a fluorescent screen, with internal or external means to accelerate and deflect the electron beam, used to create images in the form of light emitted from the fluorescent screen. • LCD: Liquid Crystal Display (LCD) is a thin, flat electronic visual display that uses light modulating of liquid crystals. Liquid crystals do not emit light directly. • LCDs have displaced cathode ray tube displays in most applications. They are usually more compact, lightweight, portable, less expensive, more reliable, and easier on the eyes. They are available in a wider range of screen sizes than CRT and plasma displays, and since they do not use phosphors, they cannot suffer image burn-in. LCDs are more energy efficient and offer safer disposal than CRTs. It has low electrical power consumption. • LED: Light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices, and are used for lighting. • PDP: Plasma display panel is a type of flat panel display common on large TV displays. They are called plasma displays because the pixels rely on plasma cells or fluorescent lamps. Plasma displays should not be confused with LCDs. LCD displays may use one or two fluorescent lamps as a backlight source, but the different colours are controlled by LCD units.