Saturday 27 May 2017

Week 10 : Basic Web Development

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Definition of HTML :

HTML (Hypertext Markup Language) is the set of markup symbols or codes inserted in a file intended for display on a World Wide Web browser page. 



HTML File

A file with the HTM or HTML file extension is a Hypertext Markup Language file and is the standard web page file type on the internet.
Since HTM files are text-only files, they just contain text (like what you're reading now), as well as text references to other external files (like the image in this article).
HTM and HTML files can also reference other files like video, CSS, or JS files.



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The picture above shows an example of HTML editor. 

HEADING
<BODY>
<H1>Level 1 Heading</H1>
<H2>Level 2 Heading</H2>
<H3>Level 3 Heading</H3>
<H4>Level 4 Heading</H4>
<H5>Level 5 Heading</H5>
<H6>Level 6 Heading</H6>
</BODY>

PARAGRAPH: center, left, right, justify
<BODY>
<p align=center>
This is a centered paragraph.
</p>
</BODY>


Friday 26 May 2017

Week 9 : Internet Applications (For Teaching and Learning)

Image result for synchronous and asynchronous communication

Source : https://www.tigerteam.dk/2014/microservices-its-not-only-the-size-that-matters-its-also-how-you-use-them-part-3/



PROS and CONS of Synchronous and Asynchronous Learning Environments :

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Week 8 : Email











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What is email?

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Email Protocols : 

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Examples of email clients 

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The picture above shows how email server works. 


Multipurpose Internet Mail Extension.

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There are a few common MIME types:

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SPAM mail 





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Week 7 : Web Searching

What is World Wide Web?

basically a system of Internet servers that support specially formatted documents. The documents are formatted in a markup language called HTML (HyperText Markup Language) that supports links to other documents, as well as graphics, audio, and video files.



the video shows how search engines work 

There are four types:

Directories
–Search engines
–Meta-search engines
–Yellow pages


What is web browser?

A web browser, or simply "browser," is an application used to access and view websites. Common web browsers include Microsoft Internet Explorer, Google Chrome, Mozilla Firefox, and Apple Safari.

A Boolean Query is a query that consists keywordsbut with logical operators(AND, OR, NOT).


Image result for boolean queries in searching


How does searching work?

User Interface–Allows you to type a query and displays the results.
• Searcher –The engine searches the database for matching your query. 

• Evaluator–The engine assigns scores to the retrieved information.

•Gatherer–The component that travels the WEB, and collects information.

•Indexer –The engine that categorizes the data collected by the gatherer








Wednesday 26 April 2017

Week 6 : Network Protocol and Standards

What is TCP?



  • there are two versions of TCP/IP, IPv4 and IPv6. 
  • 10BASE-2 (Thinwire coaxial cable with a maximum segment length of 185 meters)
  • 10BASE-5 (Thickwire coaxial cable with a maximum segment length of 500 meters)
  • 10BASE-36 (broadband multi-channel coaxial cable with a maximum segment length of 3,600 meters)
x


the video above shows how TCP/IP works.











hey guys, let's watch this amazing video about the difference between ipv4 and ipv6.

What is Ethernet (802.3)?


802.3 is a standard specification for Ethernet, a method of physical communication in a local area network (LAN), which is maintained by the Institute of Electrical and Electronics Engineers (IEEE). In general, 802.3 specifies the physical media and the working characteristics of Ethernet. The original Ethernet supports a data rate of 10 megabits per second (Mbps) and specifies these possible physical media:





the video above explain the details about Wifi 802.11

THE DIFFERENCES BETWEEN  802.11a, 802.11b, 802.11g and 802.11n


- 802.11a:
Operates in the 5.15GHz to 5.35GHz radio spectrum.
Speed: Up to 54Mbps (actual throughput is closer to 22Mbps)
Range: 50 feet
Less prone to interference.
More expensive.
Because 802.11b and 802.11a use different radio technologies and portions of the spectrum, they are incompatible with one another. 

- 802.11b: 
Operates in the 2.4GHz radio spectrum.
Speed: Up to 11Mbps
Range: 100 feet
Prone to interference (it shares airspace with cell phones, Bluetooth, security radios, and other devices).
Least expensive wireless LAN specification.
The Wireless Ethernet Compatibility Alliance (WECA) has done its part by certifying hundreds of products to make sure they work together. 

- 802.11g:
Operates in the 2.4GHz radio spectrum.
Speed: Up to 54Mbps
Range: 100 feet
Prone to interference (it shares airspace with cell phones, Bluetooth, security radios, and other devices).

- 802.11n (Draft):
Operates in the 2.4 or 5GHz radio spectrum
Speed: Up to 700Mbs
Range: 50 feet
Because 802.11b and 802.11g use the same radio technologies and portions of the spectrum, they are compatible with one another. But because the 802.11n standard has yet to be ratified by WECA, it may not be completely compatible with 802.11b and 802.11g.


How does a bluetooth connection work?

A Bluetooth  device uses radio waves instead of wires or cables to connect to a phone or computer. A Bluetooth product, like a headset or watch, contains a tiny computer chip with a Bluetooth radio and software that makes it easy to connect. When two Bluetooth devices want to talk to each other, they need to pair.


Bluetooth vs Infrared 

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Types of connection :

1) Dial-up connection
2) Direct connection



INTERNET INFRASTRCTURE

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Source : http://seri06.blogspot.my/2013/05/the-internets-infrastructure.html

example of IP Address

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USING THE NETWORK

1. company
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2. individual

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Monday 3 April 2017

Week 5 : Wired and Wireless Technology

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This chapter will explain about network characteristics : topology,wired vs wireless, size or coverage area & architecture.

  • wired network 

                     The video above shows how to connect network wired network at home.

  • wireless network






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The video tells the basic about connecting wireless network. 

There are four types of wireless networks, they are :- 

  • wireless wide area networks (WWANs)
  • wireless metropolitan area networks (WMANs)
  • wireless local area networks (WLANs)
  • wireless personal area networks (WPANs)



Different classification of wireless technologies. 


There are five types of wireless technology :
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 1) Infra Red
 - do not use signal
- Infrared Data Association 
- not popular now

2) Bluetooth
- it is for wireless personal area networks 
- for a short range <10m
- connect devices such as mobile phones, laptops, printers, PCs and so on.

3) Wireless local area networks (WLANs), Wifi
-  based on the IEEE 802.11 standard.
- it has two radio frequency specifications (RF - direct sequence and frequency hopping spread spectrum) and one infrared (IR).
- use a point-to-point solution and point-to-multi-point solution.

4) Broadband wireless
- Speed up to 70Mbps, Range 30 miles.
- Broadband means 'having instantaneous bandwidth greater than around 1 MHz and supporting
  data rates greater than about 1.5 Mbit/s.



5)Wimax 

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Sunday 19 March 2017

W4 : Connecting a Network (Cabling & Hardware)

In this chapter, it will explain about networking software, wired network-types of cables and networking and their functions.



  • wired network - types of cables 
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- coaxial cable connector uses Bayonet-Neil-Concelman (BNC) connector


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- fiber optic cable able to transmit signals over longer distances.
-it transmit light and eliminate the interference.
-for example, unifi.  
- fiber optic uses ST & SC connector.

Image result for unshielded twisted pair cable


shielded twisted pair :
- provide more reliable data communication.
- however the disadvantage is extra shielding cause large 

unshielded twisted pair :
- it has 4 pairs of wires
- it has different number of twists to remove interference.