Human ware

HUMANWARE AND FIRM WARE SOFTWARE DEVELOPMENT DATABASE MANAGEMENT AGB111 2013-14

Overview • • • • • •

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Humanware Firmware Memory Software development Operators Database networks

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Human ware The personnel which are related to installation, maintenance, operation and testing of computer are called human ware.

Example:Programmer, Hardware/Network Engineers, System Analysts

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Design of human ware • Understanding the needs and limitations of the end user and working backwards to design the final product. • Testing is done on the product to ensure that its design is enhancing the end users experience in the desired way.

Example: Technology designed to aid persons with disabilities

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Process of building humanware 1. Define users (age, mindset, environmental context, previous product experience and expectations etc.) and what they really want to do 2. Identify tasks they will need to do or capabilities they will want 3. Specify usability objectives (if possible, these should be measurable, such as how long to do something or how many mouse clicks to get to a specified task point) for each task or capability 4. Build a prototype of the user interface (it can be a paper or simulated prototype if time is short) 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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5. Test and verify or correct the prototype 6. Provide the prototype and usability objectives to the program designers and coders 7. Test the code against the prototype and objectives and, if necessary, redesign or recode the software 8. Test the product with users or valid test subjects and revise as necessary 9. Get feedback from users and continually improve the product

ďƒ˜Specially designed to interact with users, including its speech synthesis and speech recognition microchips developed by Dr. R Jayashree, Asst. Prof, 15/11/13 Philips.

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Firmware • It is the combination of persistent memory and program code and data stored in it.  Examples: embedded systems (such as traffic lights, consumer appliances, and digital watches), computers, computer peripherals, mobile phones and digital cameras.

• The firmware contained in these devices provides the control program for the device.

• Firmware is held in non- volatile memory devices such as ROM, EPROM OR FLASH MEMORY. • Some firmware memory devices are permanently installed and cannot be changed after manufacture (Pen drive) 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Memory • Refers to the physical devices used to store programs (sequences of instructions) or data • Primary memory is used for the information in physical systems which function at high-speed ie.

RAM • Secondary memory are physical devices for program and data storage which are slow to access but offer higher memory capacity.

• Primary memory stored on secondary memory is called “virtual memory".  Archaic synonym for memory is store 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Semiconductor memory • Primary memory is often associated with addressable semiconductor memory ie., Integrated circuits of silicon based transistorsin digital electronic devices.

Types of semiconductor memory: Volatile-Primary memory- RAM, Dynamic RAM,Static RAM, CPU cache memory Non-volatile- used in secondary storage devices,ROM/PROM/EPROM for boot programs 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Silicon based semiconductor

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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SOFTWARE DEVELOPMENT Standard Software packages - general-purpose applications.

Application software - for performing specific data processing or computational tasks.

The processes of developing the application software are called the Software Development Life Cycle (SDLC).

SDLC consists of six steps: •Problem Definition / Program Analysis •Program Design •Coding •Testing •Documentation •Maintenance 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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PROGRAM DESIGN It is done to meet the specified objectives- it consists of designing a solution.

Structured program design is a method of designing a computer program in such a way so as to minimize the complexity.

Among the tool used in this stage are : •Top-down program design •Flowcharts •Pseudocode 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Flowcharts • Graphically represents the logic needed to solve a programming problem.

• Represents the detailed sequence of steps, needed to solve the problem.  Program flowcharts are frequently used to visualize the logic and steps in processing 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Standard flowchart symbols

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Standard flowchart symbols

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Constant, Variables and Operators Constant: Numerical Quantities are referred as constants. It can be integers or decimal quantities.

Variables: It is a name that represents a number or a string. Its value can vary.

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Operators Three types of operators namely

1. Arithmetic Operators (+, -, /, *, **) 2. Logical Operators (<, >,=,<>,<=,>=) 3. Relational Operators (AND, OR, NOT) 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Expression â&#x20AC;˘ Constants and variables are connected using operators to form expression. â&#x20AC;˘ Example : X =A + B - (C*3)**4

Hierarchy of Operation The quantities inside a parenthesis Exponentiation Multiplication and Division in the order Addition and Subtraction in the order 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Using this rule and the two following facts,

we can deduce a new fact:

Famous declarative languages is Prolog (PROgramming in LOGic)

The user can then ask:

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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ARITHMETIC OPERATORS

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Relational operators Relational operators compare data to see if a value is greater than, less than, or equal to another valuecc

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Logical operators Logical operators combine Boolean values (true or false) to get a new value. The C language uses three logical operators

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Structured programming strongly recommends the use of the three types of control statements: sequence, selection and repetition

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R Jayashree, Asst. Prof, Two-wayDr.and multi-way decisions Veterinary College, Hebbal

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ThreeDr. Rtypes of repetition Jayashree, Asst. Prof, Veterinary College, Hebbal

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Database • Is an organized collection of related information (Collection of records) • It contains many records. Each record may contain many fields.

• Facilitates storage, retrieval and management of information.

• Basic feature of databases is that the data in a database can be organised in a systematic way such as a tabular format Database Management 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Database Management System (DBMS) • Collection of interrelated data • Set of programs to access the data • DBMS contains information about a particular enterprise • DBMS provides an environment that is both convenient and efficient to use.

• Databases touch all aspects of our lives 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Building database

â&#x20AC;˘ Uses a generalized software package called Database Management System (database, FoxPro etc.). â&#x20AC;˘ It is used to build and manage the database, i.e., add, change (edit), delete, sort and retrieve information from the database

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Database Applications – Banking: all transactions – Airlines: reservations, schedules – Universities: registration, grades – Sales: customers, products, purchases – Manufacturing: production, inventory, orders, supply chain – Human resources: employee records, salaries, tax 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Drawbacks of using file systems to store data – Data redundancy and inconsistency • Multiple file formats, duplication of information in different files

– Difficulty in accessing data • Need to write a new program to carry out each new task

– Data isolation — multiple files and formats – Integrity problems • Integrity constraints (e.g. account balance > 0) become part of program code • Hard to add new constraints or change existing ones

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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• Drawbacks of using file systems (cont.)

– Atomicity of updates • Failures may leave database in an inconsistent state with partial updates carried out • E.g. transfer of funds from one account to another should either complete or not happen at all – Concurrent access by multiple users • Concurrent accessed needed for performance • Uncontrolled concurrent accesses can lead to inconsistencies – E.g. two people reading a balance and updating it at the same time – Security problems

• Database systems offer solutions to all the above problems 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Address database In this database file there are 4 records and each record is having 3 fields.

Field 1

Field 2

Field 3

Place

Phone

Field names Name

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Ramesh

Chennai

945678

Keerthi

Maduarai

239349

Kailash

Bangalore

839495

Rama

Mysore

929304

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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DATABASE –QUERY DESIGNER

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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An architecture for a database system

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Data Models • A collection of tools for describing – – – –

data data relationships data semantics data constraints

• Entity-Relationship model • Relational model • Other models: – object-oriented model – semi-structured data models – Older models: network model and hierarchical model 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Entity Relationship Model • E-R model of real world – Entities (objects) • E.g. customers, accounts, bank branch

– Relationships between entities • E.g. Account A-101 is held by customer Johnson • Relationship set depositor associates customers with accounts

• Widely used for database design – Database design in E-R model usually converted to design in the relational model (coming up next) which is used for storage and processing 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Entity-Relationship Model -Example

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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A Sample Relational Database

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Relational Model

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Data Languages

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Database Administrator • Coordinates all the activities of the database system; the database administrator has a good understanding of the enterprise’s information resources and needs.

• Database administrator's duties include: – Schema definition – Storage structure and access method definition – Schema and physical organization modification – Granting user authority to access the database – Specifying integrity constraints – Acting as liaison with users – Monitoring performance and responding to changes in requirements Dr. R Jayashree, Asst. Prof,

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Veterinary College, Hebbal

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Transaction Management â&#x20AC;˘ A transaction is a collection of operations that performs a single logical function in a database application â&#x20AC;˘ Transaction-management component ensures that the database remains in a consistent (correct) state despite system failures (e.g., power failures and operating system crashes) and transaction failures. â&#x20AC;˘ Concurrency-control manager controls the interaction among the concurrent transactions, to ensure the consistency of the database.

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Storage Management • Storage manager is a program module that provides the interface between the low-level data stored in the database and the application programs and queries submitted to the system.

• The storage manager is responsible to the following tasks: – interaction with the file manager – efficient storing, retrieving and updating of data 15/11/13

Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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Application Architectures

Two-tier architecture: E.g. client programs using ODBC/JDBC to communicate with a database Three-tier architecture: E.g. web-based applications, and R Jayashree, Asst. Prof, applications built usingDr.“middleware” 15/11/13 43 Veterinary College, Hebbal

Overall System Structure

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Dr. R Jayashree, Asst. Prof, Veterinary College, Hebbal

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