Multimedia

Multimedia refers to content that uses a combination of different content forms. This contrasts with media that use only rudimentary computer displays such as text-only or traditional forms of printed or hand-produced material. Multimedia includes a combination of text, audio, still images, animation, video, or interactivity content forms.

Categories of multimedia:-Multimedia may be broadly divided into
1.Linear and
2.Interactive (Non-linear).

Linear active content progresses often without any navigational control for the viewer such as a cinema presentation. Non-linear uses interactivity to control progress as with a video game or self-paced computer based training. Hypermedia is an example of non-linear content.
Multimedia presentations can be live or recorded. A recorded presentation may allow interactivity via a navigation system. A live multimedia presentation may allow interactivity via an interaction with the presenter or performer.

Components of multimedia:-
1) Computer System: Workstation,MPEG/Video/DSP
2) Communication Networks : Token Ring,FDDI , Ethernet,Intranet,ATM  ,Internet
3) Display Devices :Hi-Rsolution monitors,CD-quality speakers,Colour printers,HDTV,SVGA,etc.
4) Capture devices : -Video Camera,Video Recorder ,Audio Microphone,Keyboards,Mice
5) Storage devices :- Hard disks,CD ROM,DVD,etc.

Major characteristics:-
Multimedia presentations may be viewed by person on stage, projected, transmitted, or played locally with a media player. A broadcast may be a live or recorded multimedia presentation. Broadcasts and recordings can be either analog or digital electronic media technology. Digital online multimedia may be downloaded or streamed. Streaming multimedia may be live or on-demand.

Multimedia games and simulations may be used in a physical environment with special effects, with multiple users in an on-line network, or locally with an offline computer, game system, or simulator.

The various formats of technological or digital multimedia may be intended to enhance the users' experience, for example to make it easier and faster to convey information. Or in entertainment or art, to transcend everyday experience.

Application:-Multimedia finds its application in various areas including, but not limited to, advertisements, art, education, entertainment, engineering, medicine, mathematics, business, scientific research and spatial temporal applications. 

SSD

SSD  :-

• A solid-state driveis a data storage device using integrated circuit assemblies as memory to store data persistently.

• SSD technology uses electronic interfaces compatible with traditional block input/output (I/O) hard disk drives, thus permitting simple replacement in common applications.

• SSDs have no moving (mechanical) components. This distinguishes them from traditional electromechanical magnetic disks such as hard disk drives (HDDs) or floppy disks, which contain spinning disks and movable read/write heads.

• SSDs are still roughly seven to eight times more expensive per unit of storage than HDDs.

• SSDs use NAND-based flash memory, which retains data without power.

• SSD includes a controller that incorporates the electronics that bridge the NAND memory components to the host computer.

• SSDs have no moving parts and therefore are basically silent, although electric noise from the circuits may occur.

• Susceptibility to environmental factors-No moving parts, very resistant to shock and vibration.

• Storage capacity-In 2013, SSDs were available in sizes up to 2 TB, but less costly 128 to 512 GB drives were more common.

• Power consumption-High performance flash-based SSDs generally require half to a third of the power of HDDs. High-performance DRAM SSDs generally require as much power as HDDs, and must be connected to power even when the rest of the system is shut down.

•  SSDs were mainly used in those aspects of mission critical applications where the speed of the storage system needed to be as high as possible. Since flash memory has become a common component of SSDs, the falling prices and increased densities have made it more cost-effective for many other applications. 
• Advantage :-Speed: This is where SSDs shine. An SSD-equipped PC will boot in seconds, certainly under a minute. A hard drive requires time to speed up to operating specs, and will continue to be slower than an SSD during normal operation. A PC or Mac with an SSD boots faster, launches apps faster, and has higher overall performance. 
• SSD technology has been developing rapidly.
• Typically the same file systems used on hard disk drives can also be used on solid state disks.
• While not a file system feature, operating systems must also align partitions correctly to avoid excessive read-modify-write cycles.
• A typical practice for personal computers is to have each partition aligned to start at a 1 MB mark, which covers all common SSD page and block size scenarios, as it is divisible by 1 MB, 512 KB, 128 KB, 4 KB and 512 bytes. Modern operating system installation software and disk tools handle this automatically.
• Other features designed for hard disk drives, most notably defragmentation, are disabled in SSD installations 
• HDDs win on price, capacity, and availability. SSDs work best if speed, ruggedness, form factor, noise, or fragmentation (technically part of speed) are important factors to you. If it weren't for the price and capacity issues, SSDs would be the winner hands down.
• Last but not least, an SSD and an HDD can be combined (like Voltron) on systems with technologies like Intel's Smart Response Technology. SRT uses the SSD invisibly to help the system boot faster and launch apps faster.

Notes on php

The limitations of cookies :-

1) the cokkie specification says that 

I) no cookie can exceed 4KB in size,

II) only 20 cookies are allowed per domain ,

III) and a total of 300 cookies can be stored on the client side

2) There is no control over when the browsers actually expire cookies.

Type juggling :-

1) The conversion of a value from one type to another is called casting.

2) This kind of implicit casting is called type juggling in PHP.

Regular expressions:-

1) Definition :- A regular expression is a string that represents a pattern .The regular expression functions compare that pattern to another string and see if any of the string matches the pattern .Some functions tell you whether there was a match, while others make changes to the string.

2) PHP provides support for two different types of regular expressions :

1) POSIX and 

2) Perl- compatible

3) POSIX regular expressions are less powerful and sometimes slower , than the Perl - compatible functions ,but can be easier to read.

4)There are three uses for regular expressions:

1) matching ,which can also be used to extract information from a string ;

2) substituting new text for matching text; and

3) spilitting a string into an array of smaller chunks.

5) PHP has functions for all three behaviours for both Perl and POSIX regular expressions .For instance ,erg() does a POSIX match ,while preg_match() does a Perl match .

6) Fortunately ,there are a number of similarities between basic POIX and Perl regular expressions, so we'll cover those before dealing into the details of each library. 

Serialzation:-

1) Serializing an object means converting it to bytestream representation that can be stored in a file. This  is useful for persistent data , for example , PHP sessions automatically save and restore object.

2) Serialization in PHP is mostly automatic - it requires little extra work from you.

Design pattern

Why design pattern?
To make project new libraries are created.
New classes can be used for further program i.e. Classes are reusable.
Thus the problem which is reusable is design pattern.


Definition Design Pattern
Each pattern describes a problem which occurs over and over again in our environment and then describes the code of the solution to that problem in such a way that you can use this solution a million times over without ever doing it the same way twice.

Elements of design pattern :-
1) Pattern name
2) Problem
3) Solution
4) Consequences

The person requires documentation for design pattern i.e. Describing design pattern.
For this there are as follows:-
1) Pattern name and classification
2) Intent
3) Also known as ( different names for them e.g. Abstract class has user class name )
4) Motivation ( why person problem to motivate for design pattern )
5) Applicability ( Real life situations where used )
6) Structure ( data structures )
7) Participants ( objects and components )
8 ) Collaboration (collaborate)
9) Consequences ( Advantage and disadvantages) also drawbacks
10) Implementation
11) Sample code( code of any object oriented language )
12) Known Uses
13) Related Patterns .( relationship with other design pattern)
14) Factory methods ( only methods used for design pattern)

The catalog of design pattern :-
1) Abstract factory
2) Prototype
3) Singleton ( means single object )
4) Adaptor
5) Decorator
6) Proxy
7) Command
8) Observer
9) Strategy

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LAN wire configuration

Cat 5 is required for basic 10/100 functionality, you will want Cat 5e for gigabit (1000BaseT) operation.
The ethernet cable, are 8 color coded wires.
These wires are twisted into 4 pairs of wires, each pair has a common color theme.
One wire in the pair being a solid or primarily solid colored wire and the other being a primarily white wire with a colored stripe (Sometimes ethernet cables won't have any color on the striped wire, the only way to tell which is which is to check which wire it is twisted around).
Examples of the naming schemes used are: Orange (alternatively Orange/White) for the solid colored wire and White/Orange for the striped cable. The twists are extremely important.

RJ45 :-
RJ-45 conductor data cable contains 4 pairs of wires each consists of a solid colored wire and a strip of the same color. There are two wiring standards for RJ-45 wiring: T-568A and T-568B. Although there are 4 pairs of wires, 10BaseT/100BaseT Ethernet uses only 2 pairs: Orange and Green. The other two colors (blue and brown) may be used for a second Ethernet line or for phone connections. The two wiring standards are used to create a cross-over cable (T-568A on one end, and T-568B on the other end), or a straight-through cable (T-568B or T-568A on both ends).
What is RJ stands for?
RJ stands for Registered Jacks. These are used in telephone and data jack wiring registered with FCC. RJ-11 is a 6-position, 4-conductor jack used in telephone wiring, and RJ-45 is a 8-position, 8-conductor jack used in 10BaseT and 100BaseT ethernet wiring.

Data Mining

Data mining is the computational process of discovering patterns in large data sets involving methods at the intersection of artificial intelligence,machine learning, statistics, and database systems.
It is sometimes called Knowledge Discovery in Databases (KDD) .

The Knowledge Discovery in Databases (KDD) process is commonly defined with the stages:

    (1) Selection
    (2) Pre-processing
    (3) Transformation
    (4) Data Mining
    (5) Interpretation/Evaluation


Data mining involves six common classes of tasks:

1)Anomaly detection (Outlier/change/deviation detection) – The identification of unusual data records, that might be interesting or data errors that require further investigation.

2)Association rule learning (Dependency modeling) – Searches for relationships between variables. For example a supermarket might gather data on customer purchasing habits. Using association rule learning, the supermarket can determine which products are frequently bought together and use this information for marketing purposes. This is sometimes referred to as market basket analysis.

3)Clustering – is the task of discovering groups and structures in the data that are in some way or another "similar", without using known structures in the data.

4)Classification – is the task of generalizing known structure to apply to new data. For example, an e-mail program might attempt to classify an e-mail as "legitimate" or as "spam".

5)Regression – attempts to find a function which models the data with the least error.
 
6)Summarization – providing a more compact representation of the data set, including visualization and report generation.

In business, data mining is the analysis of historical business activities, stored as static data in data warehouse databases. The goal is to reveal hidden patterns and trends.

In recent years, data mining has been used widely in the areas of science and engineering, such as bioinformatics, genetics, medicine, education and electrical power engineering.

Data mining of government records – particularly records of the justice system (i.e., courts, prisons) – enables the discovery of systemic human rights violations in connection to generation and publication of invalid or fraudulent legal records by various government agencies.

Solved quetions

1.Find the wrong number in the sequence: 52, 51, 48, 43, 34, 27, 16
(A) 27
(B) 34
(C) 43
(D) 48

Answer:- (B) 34

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2.In a certain code ,PAN is written as 31 and PAR as 35,then PAT is written in the same code as
(A) 30
(B) 37
(C) 39
(D) 41

Answer :- (B) 37

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3.The letters in the first set have certain relationship. On the basis of this relationship,make the right choice for the second set :AF:IK: :LQ:?
(A )MO
(B) NP
(C) OR
(D) TV

Answer :-(D) TV

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4.If 5472=9, 6342=6, 7584=6,what is 9236?
(A) 2
(B) 3
(C) 4
(D) 5

Answer :- (A) 2

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5.1 GB is equal to
(A) 2 ³⁰ bits
(B) 2 ³⁰ bytes
(C) 2 ²⁰ bits
(D) 2 ²⁰ bytes

Answer :- (B) 2 ³⁰ bytes

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6.The set of computer programs that manage the hardware/software of a computer is called
(A) Compiler system
(B) Operation system
(C) Operating system
(D) None of these

Answer :- (C) Operating system

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7.S/MIME in Internet technology stands for
(A) Secure Multipurpose Internet Mail Extension
(B) Secure Multimedia Internet Mail Extension
(C) Simple Multipurpose Internet Mail Extension
(D) Simple Multimedia Internet Mail Extension

Answer :- (A) Secure Multipurpose Internet Mail Extension

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8.Which one of the following is not an Internet Service Provider(ISP)?
(A) MTNL
(B) BSNL
(C) ERNET India
(D) Infotech IndiaLtd.

Answer :- (D) Infotech IndiaLtd.

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9.The hexadecimal number system consists of the symbols
(A) 0 – 7
(B) 0 – 9 ,A–F
(C) 0– 7,A-F
(D) None of these

Answer :- (B) 0 – 9 ,A–F

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10.The binary equivalent of (–15)₁₀ is (2’s complement system is used)
(A) 11110001
(B) 11110000
(C) 10001111
(D) None of these

Answer :- (A) 11110001

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