E-Commerce

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 questions

Tablet

Today's tablet computers sport touch screens ranging in size from 7- up to 13-inches. These dimensions are by no means static, and boundaries can be blurred as smartphones get larger displays

Features of tablet :-
I) Hardware :-
1. High-definition, anti-glare display
2. Wireless local area and internet connectivity (usually with Wi-Fi standard and optional mobile broadband)
3. Front- and/or back- facing camera(s) for photographs and video
4. Lower weight and longer battery life than a comparably-sized laptop
5. Bluetooth for connecting peripherals and communicating with local devices
6. Early devices had IR support and could work as a TV remote controller.
7. Docking station: Keyboard and USB port(s)

Note:-
Special hardware: The tablets can be equipped with special hardware to provide functionality, such as camera, GPS and local data storage.

II) Software :-
1. Mobile web browser
2. Reader for digital books, periodicals and other content
3. Downloadable apps such as games, education and utilities
4. Portable media player function including video playback
5.  Email and social media
6. Mobile phone functions (messaging, speakerphone, address book)
7. Video-teleconferencing

III) Data storage :-
1. On-board flash memory
2. Ports for removable storage
3. Various cloud storage services for backup and syncing data across devices
4. Local storage on a LAN

IV) Additional inputs :-
Besides a touchscreen and keyboard, some tablets can also use these input methods:
1. Proximity sensor to detect if the device is close to something, in particular, to your ear, and can block unintended touches
2. Accelerometer: Detects the physical movement and orientation of the tablet. This allows the touchscreen display to shift to either portrait or landscape mode. In addition, tilting the tablet may be used as an input (for instance to steer in a driving game)
3. Ambient light and proximity sensors, which help distinguish between intentional and unintentional touches
4. Speech recognition
5. Gesture recognition
6. Character recognition to allow you to write text on the tablet, that can be stored as any other text in the intended storage, instead of using a keyboard.


To run your tablet smoothly:
1. Remove unnecessary apps and make more room.
2. Disable flashy settings that don’t really serve any important purpose.
3. Keep your screen clean (literally and virtually).
4. Format your external storage on a regular basis.

To install OS on your Tablet you need Android OS file that are compatible with your tablet and Software tools:
Memory card has to be made bootable. For this the PhoenixCard tool is needed.
First format the memory card, then select the  compatible Android ISO file. Please note that different tablet need different ISO files.

iPad

The iPad is not a replacement for a laptop. Tablets are good at many things, but their abilities are a subset of a laptop's. You can't, for example, burn a music CD to listen to in the car, or a DVD of your latest home movie. It isn't particularly easy to print from an iPad, either, although it is possible in some apps (you can print an email, a document or a web page if you have a compatible printer).

Features of iPad or Advantages of iPad: 
1)Battery life:
With an iPad, you'll be freed from the mains all day, since it will last for at least eight (if not 10 or 12) hours of constant use.
2)Portability and comfort:
It's more comfortable to sit and use an iPad, it doesn't get too warm and there are no fans, unlike most laptops whose high-pitched fans can drive you to distraction.
3)Touchscreen interface :
You can type very fast on the iPad's virtual, on-screen keyboard.The iPad's interface is, in general, hugely intuitive.
4)Instant on and connected standby:
An iPad doesn't take minutes to boot up: it's ready to go instantly, so it's quick to check email and Facebook, or the weather forecast or TV listings.

Disadvantages of iPad: 
1) Storage:
The iPad has no way of adding storage, so you're effectively stuck with the capacity you buy.
2)File formats:
 The iPad is much more restrictive and requires videos, for example, to be in MP4 (H.264) format before they'll play. It means you might have to convert files before you can play them, which could be more hassle than you're willing to accept.
For photos and music, the iPad supports the common JPG and MP3 formats, so these aren't a problem for most people.

Education and healthcare
The iPad has several uses in the classroom, and has been praised as a valuable tool for homeschooling.Soon after the iPad was released, it was reported that 81% of the top book apps were for children. The iPad has also been called a revolutionary tool to help children with autism learn how to communicate and socialize more easily.
In the healthcare field, iPads and iPhones have been used to help hospitals manage their supply chain. For example, Novation, a healthcare contracting services company, developed VHA PriceLynx (based on the mobile application platform of business intelligence software vendor MicroStrategy), a business intelligence app to help health care organizations manage its purchasing procedures more efficiently and save money for hospitals. Guillermo Ramas of Novation states, "Doctors won't walk around a hospital with a laptop. With an iPad it's perfect to walk around the hospital with as long as they have the information they need."
In 2013, Gianna Chien (aged 14) presented to more than 8,000 doctors at the Heart Rhythm Society meeting that Apple iPad 2 can, in some cases, interfere with life-saving heart devices (pace maker) because of the magnets inside. Apple's webpage has advised pacemaker users to keep iPads at least 6-inches away from the pacemaker.

iBooks
The iPad has an optional iBooks application that can be downloaded from the App Store, which displays books and other ePub-format content downloaded from the iBookstore.

Internet connectivity in iPad:
The iPad can use Wi-Fi network trilateration from Skyhook Wireless to provide location information to applications such as Google Maps. The 3G model supports A-GPS to allow its position to be calculated with GPS or relative to nearby cellphone towers; it also has a black strip on the back to aid 3G reception. The iPad has a headphone jack and a proprietary Apple dock connector, but no Ethernet or USB port. However, the Apple Camera Connection Kit accessory provides two dock connector adapters for importing photos and videos via USB and SD memory cards.