Wednesday, October 10, 2012

What is an Algorithm?

We saw above that planning a program involves defining its logic (the correct sequence of instructions needed to solve the problem at hand).The term algorithm is often used to refer to the logic of a program. It is step-by step description of how to arrive at the solution of the given problem. It may be formally defined as a sequence of instruction, designed in a manner that, if the instruction is executed in the specified sequence, the desired results will be obtained. In order to qualify as an algorithm, a sequence of instructions must possess the following characteristics:

1.    Each and every instruction should be precise and unambiguous.
2.    Each instruction should be such that it can be performed in a finite time
3.    One or more instructions should not be repeated infinitely. This ensures that the algorithm will ultimately terminate.
4.    After performing the instruction, that is, after the algorithm terminate, the desired results must be obtained.

Sample Algorithms

What is computer algorithm
To gain insight in to algorithms, let us consider some simple examples


50 students in a class appeared in their final examination.Their mark sheets have been given to yo.The division column of the mark sheet contains the division(FIRST,SECOND,THIRD or FAIL) obtained by the student.Write an algorithm to calculate and print the total number of students who passed in FIRST  division.

Step:- 1  Initialize Total_First_Division and Total_Marksheets_Checked to zero.
Setp:- 2 Take the mark sheet of the next student.
Step:- 3 Check the division column of the mark sheet to see if it is FIRST.If no,go to Step 5.
Step:- 4 Add 1 to Total_First_Division
Step:- 5 Add 1 to Total_Marksheets_Checked.
Step:- 6 Is Total_Marksheets_Checked= 50? If no, go to Step2.
Step:- 7 Print Total_First_Division.
Step:- 8 Stop

Thursday, September 13, 2012

10 Security Design Principle for your Computer

We have seen that security is guarding use’s data and programs against interface by entities external to a system like unauthorized person. Thus security designs provide need special emphasis.

security for computers

In general, security measures include control and monitoring of physical access to the computer premises as well as the internal, computer system security. External or physical security includes the standard techniques of fencing, surveillance, authentication, and attendance monitoring. Additional access restriction may be imposed in special areas, such as the computer center and storage areas for backup volumes Physical security may also include measures for disaster recovery. Which often amount of replication of critical data and equipment at geographically dispersed locations to minimize exposure to the consequences of disasters such as fire or flood .Seltzer and Schroeder (1975) have identified the following general design principles for protection mechanisms.
speed up a pc

1. Least privilege

 Every subject should use the least set of privileges necessary to complete its task. This principle limits the damage from Trojan horse attacks. It effectively advocates support for small protection domains and switching of domains when the access needs change.

2. Separation of privilege

When possible, access to objects should depend on satisfying more than one condition.

3.Least common mechanism

This approach advocates minimizing the amount of mechanism common to and depended upon by multiple users, Design implication, include the incorporation of techniques for separating users, such as logical separation via virtual machines and physical separation on different machines in distributed systems

4.Economy of mechanism

Keeping the design as simple as possible facilitates verification and correct implementations.

5.Complete mediation

Every access request for every object should be checked for authorization, the checking mechanism should be efficient because it has a profound influence on system performance.

6.Fall-safe default

Access rights should be acquired by explicit permission only, and the default should be back of access.

7.Open design

The design of the security mechanism should not be secret, and it should not depend on the ignorance of attackers, this implies the use o cryptographic system where the algorithms are known but the keys are secret.

8.User acceptability

The mechanism should provide case of use so that it is applied correctly and not circumvented by users.

9.User Friendlily

Computer System security mechanism include authentication, access control, flow control auditing and cryptography.

10. Other

To which the user is supposed to apply a secret transformation,such as squaring and incrementing the value.Failure to do so may be used to detect unauthorized users.

Saturday, September 8, 2012

What is Computer Processor

Processors are now being built with even faster ratings. With all other parameters being equal (although they never are) a CPU operating at 500 MHz can process data five times as fast as one operating at 100 MHz
What Is Processors

Types of Processors

CISC Processors

One of the earlier goals of CPU designers was to provide more and more instructions in the instruction set of a CPU, to ensure that the CPU directly supports more features, making it easier to translate high level language programs to machine language, and to ensure that the machine language programs run more effectively. Of course every additional instruction in the instruction set of a CPU requires the necessary hardware circuitry to handle that instruction, adding more complexity to the CPU’s hardware circuitry. Another goal of CPU designers was to optimize the usage of expensive memory. To achieve this, the designers tried to pack more instruction in memory, by introduction the concept of variable-length instructions such as half word, one and half word, etc.
Types of processors

For example and operand in an immediate instruction needs fewer bits, and can be designed as half word instruction. Additionally, CPU,s were designed to support a variety of addressing modes .CPUs with large instruction set, variable  length instructions and a variety of addressing modes are said to employ CISC(Complex instruction set computer) architectures, Since  CISC processors posses so many processing features, they make the job of machine language programmers easier. However they are complex and expensive to produce. Most personal computers of today use CISC processors.

RISC Processors

In early 1980;s Some CPU designers discovered that several of the instruction supported by a CISC-based CPU are rarely used. Hence they came out with an idea that the complexity of CPU design can be greatly reduced, by implementing only a bare minimum basic set of instructions, plus some of the more frequently used instructions in the hardware circuitry of the CPU. Other complex instructions need not to be supported in the instructions set of the CPU, because they can always be implemented in software, by using the basis set of instructions.
Internet Computer Processors
 While working on simpler CUP design. These designers also came up with the idea of making .All the instructions of uniform length, so that the decoding and execution of all instructions become simple fast. Furthermore, to speed up computation, and to reduce the complexity of handling a number of addressing modes, they decided to design all the instructions in such a way that they retrieve operands stored in registers in CPU, rather than from memory. These design ideas resulted in producing faster and less expensive processors. CPUs with a small instruction set, fixed-length instructions, and reduced reference to memory to retrieve operands, are said to employ RISC(Reduced Instruction Set Computers)architure, Since RISC processors have a small instruction set, they place extra demand on programmers, who must consider how to implement complex computations by combining simple instructions. However, due to simpler design, RISC processors are faster for most application, less complex and less expensive to produce than CISC processors.

EPIC Processors

EPIC Processor
The Explicitly Parallel Instruction Computing (EPIC) technology breaks through the sequential nature of conventional processor architectures, by allowing the software to communicate explicitly to the processor, when operations can be done in parallel. For this, it uses tighter coupling between the complier and the processor, and enables the compiler to extract maximum parallelism in the original code, and explicitly describe it to the processor. Processors based on EPIC architecture are simpler and more powerful than traditional CISC or RISC processors. These processors are mainly targeted to next-generation, 64-bit high-end server and workstation market (not for personal computer market).

Thursday, August 30, 2012

What is Registers in Computer Architecture


As the instructions are interpreted and executed by the CPU, there is a movement of information between the various units of the computer system. In order to handle this process satisfactorily, and to speed up the rate of information transfer, the computer uses a number of special memory units, called registers. These registers are used to hold information on temporary basis, and are part of the CPU (not main memory).
The length of a register equals the number of bits it can store. Hence, a register that can store 8 bits is normally referred to as 8-bit register. Most CPU sold today, have 32-bit or 64-bit registers. The size of the registers is sometimes called the world size. The bigger the world size, the faster the computer can process a set of data. With all other parameters being same, a CPU with 32-bit registers, can process data twice as fast as one with 16-bit registers.

Registers in computer

Although, the number of registers varies from computer to computer, there are some registers, which are common to all computers. The functions of these registers are described below.


Memory Address Register (MAR)

- It holds the address of the active memory location. It is loaded from the program control register, when an instruction is read from memory.

Memory Buffer Register (MBR)

- It holds the contents of the memory world read from, or written in, memory. An instruction world placed in this register is transferred to the instruction register. A data word placed in this register is accessible for operation with the accumulator register, or for transfer to the I/O register.A word to be stored in memory location must first be transferred to the MBR, from where it is written in memory.

Program Control Register (PC)

- It holds the address of the next instruction to be executed Normally, the instructions of a program are stored in consecutive memory location, and read and executed in sequence, unless a branch instruction is encountered. A branch instruction is an operation, which calls for a transfer to a non-consecutive instruction. The address part of a brands instruction is transferred to the PC register, to become the address of the next instruction.

Accumulator Register (A)

- It holds the data to be operated upon, the intermediate results and the results of processing. It is used during the execution of most instructions. The results of arithmetic operations are returned to the accumulator register, for transfer to main memory, through the memory buffer register. In many computers, there are more than one accumulator registers.

Computer Architecture in Computer and Registers

Instruction Register (I)

- It holds the current instruction, which is being executed. As soon as the instruction is stored in this register, the operation part and the address part of the instruction are separated. The address part of the instruction is sent to the MAR. While its operation part is sent to the control unit, where it is decoded and interpreted, and ultimately command signals are generated to carry out the task specified by the instruction.

Input/output Register (I/O)

-It is used to communicate with the input/output devices. All input information, such as instructions and data, are transferred to this register by an input device. Similarly, all output information, to be transferred to an output device, is found in this registers.

Name of Register
Memory Address(MAR)
Holds the address of the active memory location
Memory Buffer(MBR)
Holds information on its way to and from memory
Program Control(PC)
Holds the address of the next instruction to be executed
Accumulators results and data to be3 operated upon
Holds an instruction, while it is being executed.

Communicates with the I/O devices

What is instruction sets in computer architecture

Every CPU has built-in-ability to execute a set of machine instructions, called instructions set. Most CPUs have 200 or more instructions (such as add, substract, and compare) in instruction set. The machine language designed for a processor (CPU), is based on the list of instructions supported by the CPU in its instructions set. Since each processor (CPU).is based on the list instructions supported by the CPU in its instructions set, Since each processor has a unique instruction set, machine language programs written for one computer will generally not run on another computer, with a different CPU.
What is Instruction Sets in Computer

CPUs made by different manufacturers have different instructions sets. In fact, different CPU models of the same manufacturer also often have different instructions sets. However, manufacturers tend to group their CPUs into “families”, which have similar instructions sets. When a new CPU is developed, it it ensured that its instructions set includes all the instructions in the instruction set of its predecessor Crumples some new ones. This manufacturing strategy is known as upward compatibility, and the new CPU is said to be upward compatible with its predecessor. This feature allows software written for a computer with a particular CPU, to work on computers with newer processors of the same family. In turn, it allows the users of these computer systems to easily upgrade their system, without worrying about converting all their existing software.NSK2VZ4KNRW6

Wednesday, August 29, 2012

What is central processing unit (CPU) how it is work

The CPU is the brain of a computer system. All major calculations and comparisons performed by a computer are carried out inside its CPU.
 The CPU is also responsible for activating and controlling the operation of other units of the computer system. Hence, no other single component of a computer determines its overall performance ,as much as the CPU, In order to be able to quickly evaluate any computer capabilities it is important to know how CPU are internally structured how different CPUs differ from each other ,and how CPU speed is evaluated. These and other related concepts about CPU are described below.

The Control Unit.

We saw that the two basic components of a CPU are the control unit and the arithmetic logic unit. The control unit of the CPU selects and interprets program instructions, and then sees that they are executed. It has some special purpose registers (whose functions are described in a latter subsection), and a decoder to perform these activities. The special purpose registers, namely the Instructions register and the program control register, respectively hold the current instruction and the next instruction to be executed, and in this way help the control unit in instruction selection. On the other hand. The decoder has the necessary circuitry to decode and interpret the meaning of every instruction supported by the CPU. Each instruction is accompanied by microcode—very basic directions. Which tell the CPU how to execute the instruction?
Although, the control unit does not perform any actual processing of the data, it acts as a central nervous system for other components of the computer. It manages and coordinates the entire computer system, including the input and output units. It obtains instructions from the program stored in the main memory, interprets the instructions, and issues signal, which cause other units of the system to execute them.

The Arithmetic Logic Unit (ALU)

The ALU of the CPU is the place, where the actual execution of the instructions takes place, during the data procession operation. That is, when the control unit encounters an instruction, which involves an arithmetic operation (such as, add, subtract, multiply, divide), or a logic operation (such as less than, equal to, greater that), it passes control to the ALU. The ALU has some special purpose registers and the necessary circuitry, to carry out all the arithmetic and logic operations, which are included in the instructions supported by the CPU. For example, the arithmetic and logic operations, which are included in the instructions supported by the CPU.For example, the control unit might load two numbers into the registers in the ALU.Then, it might the ALU to add the two numbers (an arithmetic operations), or to check if the two numbers are equal (a logical operation).

In case of a microcomputer, the entire CPU (both the control unit and the ALU) is contained on a single tiny silicon chip, called a microprocessor.

Wednesday, May 2, 2012

Computer Security System for your Small Business

Computer Security

This is basically a branch of computer technology also referred to as information security as applied to computer systems and network infrastructures. The main objective behind computer security entails protecting information and property from natural disaster, corruption, or theft while at the same time allowing information and property to be accessible and productive to its legitimate users.
Most computer systems are targets for intruders because these very intruders want to access what is stored in these systems. Some of the possible target information in a computer system includes information such as bank account numbers, credit/debit cards, and social security numbers among other vital details. Whenever such kind of information is unlawfully obtained by an intruder, they can be used to make transactions illegally.

Intruders not only target money related information, they are also after computer resources such as fast internet connection, fast processing speed and huge hard disk space. These intruders have devised ways whereby they can use these particular resources to attack other systems on the network. It can be said that the more intruders use computer systems to facilitate their attacks, the more difficult it becomes for law enforcement agencies to figure out where the attack is originating from.

Intruders are very much inclined to attack home and small business computer systems because in most cases these systems are rarely secured and very easy to hack into.

Often an intruder accesses computer systems remotely by sending e-mail messages containing virus attachments that when a user unknowingly reads the email, they automatically activate the virus program hence creating a loophole which can be exploited by intruders to remotely access the computer system. In some other cases, intruders may take advantage of software vulnerabilities in order to gain access. Immediately these intruders gain access to the system and they often install spyware programs that enable them to continue using the computer system even if the original loopholes have been patched.

Securing the computer system

There are quite a number of tasks that system users need to undertake in order to ensure that their computer system is fully secured. These include:

Installing and using Antivirus programs

Antivirus applications come with the unique ability to search for the contents of each file and these softwares are programmed to look for some specific patterns that match a certain profile known as the virus signature. When the antivirus detects any file that matches this particular virus signature, the antivirus application will automatically provide several options on how to respond and this may include deleting the entire file, or just removing the offending patterns.

Ensure the system is patched

Most software vendors provide software patches which can be used to seal security loopholes in software applications. As a system user you have to periodically consult your software vendor to see if there are any available patches.

Ensure utmost care when reading e-mail attachments

Most unsolicited e-mails are usually sent to unsuspecting recipients and these mails may contain return addresses, provocative subjects, or something which encourages the recipient to open the e-mail immediately. Such a technique is known as social engineering. Social engineering is compounded by the fact that most e-mail recipients are curious and trusting to open and read their mails.

Installing firewalling programs

The firewall functions more or less like a guard on the computer network. This program comes with a unique ability to filter any unwanted traffic from the network and only allow for required traffic that is perceived to be legitimate. Other computer security techniques entail backing up important files and folders, using strong authentication mechanisms, ensuring maximum care when downloading and installing applications and integrating file encryption programs and access controls.NSK2VZ4KNRW6

Sunday, February 19, 2012

Top 10 Tips-How To Protect your Computer

With Increased uses of the internet, there is a remarkable increase in online threats. It’s extremely crucial that you keep your computer safe from these threats. We are presenting 10 tips to keep your computer safe.

1. First and the foremost precautionary measure for keeping your computer safe is to invest in an antivirus program. Antivirus program will protect you from viruses and will help in avoiding any data loss or data corruption because of Virus infections. There is a new product line offered by all the Anitivirus vendors, called internet security. Internet security products protect you from antivirus, malwares and adwares.
2. Do not open suspicious email attachments. Many spam emails contain infected attachments. Make use of junk email filter and always block sender’s who send you infected emails.
3. Always install purchased software’s. Pirated software possesses threat and source files may be infected. Do not use keygens and cracks to activate pirated software’s.
4. Always scan email attachments, portable drives and CD/DVD media before copying data on your computer.
5. Do not download any suspicious files from websites, files with extensions like .scr, .vbs are executable files and are very common source of virus infection.
6. Always backup your data. This will help you to restore it in case your computer gets infected, and your data get corrupt. There are many online backup solutions available these days, which are cheap and easy to use.
7. Be aware of phishing emails. Such emails come from forged email addresses and often ask you to update your bank information or some other critical information like your email password. Information gathered using phishing emails can be exploited by the sender.
8. Use safe browsing practices. Install a pop-up blocker to disable advertisements, which lead to potentially dangerous sites. Keep your browser up to date to keep it secure, as many browsers these days release frequent updates to address the security issues. Keep your operating system updated with latest service pack and patches.

9. Do not share your personal information like phone numbers, bank details and passwords over messenger as many messengers do not encrypt the messages. The messages travel in plain text and can be hacked. Share sensitive data via email using encrypted email. There are some free encrypted email sending options available these days. is one which is free and easy to use for sending encrypted emails.
10. Use a firewall on your computer and keep an eye on the traffic coming in, and going out of your computer. Block suspicious traffic. You can use hardware or software based firewalls. Windows come with an inbuilt firewall.

Tips on how to Speed up your Computer

Being a computer user, you always keep on finding ways to speed up your computers. Slow computer always results in spending more time in getting simple jobs done and results in low productivity. In many cases, the slowness is not related to computer hardware, it’s the junk and lack of organizing your stuff with the time that lead to slowness. We are presenting you 15 tips to speed up your computer.

1. Antivirus program: Always pay for an Antivirus program. If you cannot afford to go for a paid program, some of the top Antivirus Vendors like Avast and AVG provides a free Antivirus product, which is free for home usage. Viruses cause slowness and sometimes complete corruption of data on your computer. You risk everything if you do not have an antivirus program installed.

2. Unwanted Programs: Are you in a habit of downloading new programs and testing them? Every software you download and install for testing is taking up space, and in many cases it also modify the registry to run files at startup which eats your RAM. Make a habit to uninstall the programs you do not need.

3. Defragmentation: When you install a program or copy and save files on your computer the data is written to the closest available space and it results in fragmentation on your hard disk. Defragmentation process organizes the files on your hard drive and places the files together for faster access. You should defrag your computer frequently. There are many free utilities available to automate the process.

4. Disk Cleanup: If you are not a geek, Disk cleanup utility which comes free, with every version of windows can help you to cleanup junk files from your computer. You can find it under Startup Programs-> Accessories-> System tools.

5. Updates: Keep your system updates with latest patches. Keep your drivers updated. This will help you to run your computer at its optimum level. OS patches keep you safe from online threats and Virus infections. You can enable Automatic updates to update your system weekly.

6. Backup old data to External Drives: As External storage is cheap and very affordable these days, it’s always good to keep your old data on external storage and keep your computer free from unwanted or old data.

7. Upgrade Memory: Memory upgrade can give you significant boost. With Memory prices coming down, it’s always good to have more RAM in your system. More RAM helps in faster execution of programs.

8. Disable Startup Programs: To speed up the computer boot process, it’s always good to disable unwanted startup programs. You can do it by launching MSConfig utility.

9. Disable Indexing or Tweak the Indexing settings: Indexing files on your computer may result in slow performance. You should either disable Indexing or tweak settings so that indexing runs only when your computer is idle.

10. Multitasking: Depending on your computer hardware, you can run multiple programs up to a certain limit. Avoid using multiple instances of programs like Photoshop, illustrator, video editors and virus scanners at the same time.

11. Regular scanning: Schedule scanning your computer for any malware and adware programs. Malware and adware slow down your computer and sometimes result in frequent crashing of the application and computer.

12. You can use the sleep or hibernate mode to speed up the boot process.

13. Do not install unwanted Add-ons and themes

14. Do not browse potentially danger websites. Sites, which distribute pirated software’s and cracks are potentially dangerous sites and may infect your pc by exploiting vulnerabilities.

15. You can always use some tune up software’s like Advanced system care or Tune up utilities, these software’s scan your system and suggest you many tweaks, which you can apply with a single click to speed up your computer.

Friday, January 20, 2012

What is OS (Operating system)?

An operating system (often referred to as OS) is an integrated set of programs that controls the resources (the CPU, memory, I/O devices, etc) of a computer system and provides its users with an interface or virtual machine that is more convenient to use than bare machine. According to this definition, the two primary objectives of an operating system are:

1.       Makin a computer system convenient to use- An operating system is a layer of software on top of the bare hardware of a computer system, which manages all parts of the system, and presents to the user with an interface or virtual machine, which is easier to program and use. That is, the operating system hides the details of the hardware resources from the programmer and provides the programmer with a convenient interface for using the computer system. It acts as an intermediary between the hardware and its users, providing a high-level interface to low-level hardware resources, and making it easier for the programmer and other users to access and use those resources.

The logical architecture of a computer system is shown in figure………..

As shown in the figure, the hardware resources are surrounded by the operating system layer, which in turn is surrounded by a layer of other system software (such as compilers, editors, utilities, etc.)and a set of application programs(such as commercial data processing applications, scientific and engineering applications, entertainment and educational applications,etc).Finally, the end users view the computer system in term of the user interfaces provided by the application programs.

2.       Managing the resources of a computer system. The second important objective of an operating system is to manage the various resources of the computer system. This involves performing such tasks as keeping track of who is using which resource, granting resource requests, accounting for resource usage, and mediating conflicting requests from different program and users. The efficient and fair sharing of resources among users and/or program is a key goal of most operating systems.

Main Functions of an Operating System

The main functions performed by most operating systems of today are as follows:

1.       Process Management- The process management module of an operating system takes care of the creation and deletion of process, scheduling of various system resources to the different processes requesting them, and providing mechanisms for synchronization and communication among process.

2.       Memory Management- The memory management module of an operating system takes care of the allocation and deallocation of memory space to the various programs in need of these resources.

3.       File Management-The file management module of an operating system takes care of file-related activities such as organization, storing, retrieval, naming, sharing, and protection of files.

4.       Security – The security module of an operating system protects the resources and information of a computer system against destruction and unauthorized access.

5.       Command Interpretation – The command interpretation module of an operating system takes care of interpreting user commands, and directing the system resources to handle the requests. With this mode of interaction with the system, the user is usually not too concerned with the hardware details of the system.

In addition to the above listed major functions, an operating system also performs few other functions such as keeping an account of which users (or process) use how much and what kinds of computer resources, maintainance of log system usage by all users, and maintenance of internal time clock.

Measuring System Performance

The efficiency of an operating system and the overall performance of a computer system are usually measured in terms of the following:-
1.                               Throughput – Throughput is the amount of work that the system is able to do per unit time. It is measured as the number of process that is completed by the system per unit time. For example, if n processes are completed in an interval of t seconds, the throughput is taken as n/t process per second during that interval.Throughtput is normally measured in process/hour. Note that the value of throughput does not depend only on the capability of a system, but also on the nature of jobs being processed by the system. For long process, throughtput may be one process/hour: and for short processes, throughtput may be 100 process/hour.
2.                               Turnaround time – From the point of view of an individual user, an important criterion is how long it takes the system to complete a job submitted by him/her. Turnaround time is the interval from the time submission of a job to the system for processing to the time of completion of the job.Although, higher throughput is desirable from the point of view of overall system performance. Individual users are more interested in better turnaround time for their jobs.
3.                               Response time - Turnaround time is usually not a suitable measure for interactive systems, because in an interactive system process can produce some output early during its execution and can continue executing while previous results are being output to the user.Hence, another measure used in case of interactive systems is response time, which is the interval from the time of submission of a job to the system for processing to the time the first response for the job is produced by the system.
In any computer system, it is desirable to maximize throughput and minimize turnaround time and response time.
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Sunday, January 8, 2012

Computer Animation Tutorial,2D,3D

Some typical applications of computer-generated animation are entertain-ment (motion pictures and cartoons), advertising, scientific and engineering studies and training and education. Although we tend to think of animation as implying object motions, the term Computer Animation generally refers to any time sequence of visual changes in a scene. In addition to changing object position with translations or rotations a computer-generated animation could dis-play time variations in object size, color, transparency, or surface texture.Adver-tising animations often transition one object shape into another.:- For Example, transforming a can of motor oil into an automobile engine, Computer animations can also be generated by changing camera parameters, such as position, orientation and focal length. And we can produce computer animations by changing lighting effects or other parameters and procedures associated with illumination and rendering.

Many applications of computer animation require realistic display. An ac-curate representation of the shape of thunderstorm or other natural phenomena described with a numerical model is important for evaluation the reliability of the model Also, simulators for training aircraft pilots and heavy equipment operators must produce reasonably accurate representations of the environment. Entertainment and advertising applications, on the other hand, are sometimes more interested in visual effects. Thus, sciences may be displayed with exaggerated shapes and unrealistic motions and transformations. There are many entertain-ment and advertising applications that do require accurate representations for computer generated scences.And in some scientific and engineering studies, real-ism is not a goal. For example, physical quantities are often displayed with pseudo-colors or abstract shapes that change over time to help the researcher un-distant the nature of the physical process.

Design of Animation Sequences

In general, an animation sequence is designed with the following steps:-

·         Storyboard layout

·         Object definitions

·         Key-frame specifications

·         Generation of in-between frames

This standard approach for animated cartoons is applied to other animation applications as well, although there are many special applications that do not follow this sequence. Real time computer animations produced by flight simulators, for instance, display motion sequences in response to settings on the aircraft controls. And visualization applications are generated by the solutions of the numerical models. For frame-by frame animation, each frame of the scene is separately generated and stored.Later, the frames can be recorded on film or they can be consecutively displayed in “real time playback” mode.

The storyboard is an outline of the action. It defines the motion sequence as a set of basic events that are to take place. Depending on the type of animation to be produced, the storyboard could consist of a set of rough sketches or it could be a list of the basic ideas for the motion.

An object definition is given for each participant in the action. Objects can be defined in terms of basic shapes, such as polygons or splines.In addition; the associated movements for each object are specified along with the shape.

A key frame is a detailed drawing of the scene at a certain time in the animation sequence. Within each key frame, each object is positioned according to the time for that frame. Some key frames are chosen at extreme positions in the action; others are spaced so that the time interval between key frames is not too great. More key frames are specified for intricate motions than for simple, slowly varying motions.

In between are the intermediate frames between the key frames. The number of in betweens needed is determined by the media to be used to display the animatin.Film requires 24 frames per second, and graphics terminals, are re-freshed at the rate of 30 to 60 frames per second. Typically time intervals for the motions are set up so that there are from three to five in betweens for each pair of key frames. Depending on the speed specified for the motion, some key frames can be duplicated. For a 1-minute film sequence with no duplication, we would need 1440 frames. With five in between film sequence with no duplication, we would need 1440 frames. With five in between for each pair of key frames, we would need 288 key frames. If the motion is not too complicated, we could space the key grams a little farther apart.

There are several other tasks that may be required, depending on the application. They include motion verficatin, editing, and production and synchronization of soundtrack. Many of the functions needed to produce general animations are now computer generated. Please check Example of Computer generated frames for animation sequences……

General Computer Animation Functions

Some steps in the development of an animation sequence are well suited to computer solution. These include object manipulations and rendering, camera motions and the generation of in between, Animation packages, such as Wav-front for example, provide special functions for designing the animation and processing individual objects.

One function available in animation packages is provided to store and manage the object database. Object shapes and associated parameters are stored and updated in the database. Other object functions include those for motion genera-tion and those for object rendering. Motions can be generated according to specified constraints using two-dimensional or three-dimensional transformations, Standard functions can then be applied to identify visible surfaces and apply the rendering algorithms.

Another typical function simulates camera movements. Standard motions are zooming, panning, tilting.Finally, given the specification for the key frames; the in-betweens can be automatically generated.
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