Session5 XML

About XML
Mark-up is additional information that allows users to attach particular meaning to text in a document. In order to identify exactly how the mark-up is interpreted, there are different types of mark-up languages. One of them is the Standard Generalized Markup Language (SGML) which is designed to define meaning by using angle brackets ‘<>’. SGML requires a lot of effort to adopt, whereas XML (extensible Markup Language) is much more easy to introduce.
XML includes a series of tags comprising of ‘Elements’ and ‘Attributes’. Anchor tag ‘’ is one example.In this case, ‘’ is element and ‘href’ is attribute and attribute has its own value ‘http://www.city.ac.uk/’.

XML must be ‘Well-formed’ and ‘Valid’
XML has 2 requirements that must be met. These are well-formed and valid. First, in order to be well-formed XML document, there are some criteria that need to be met. Fore example all tags must be closed, organized hierarchically and derived from a single root element. Secondly, XML document must be structured according to declaration which is commonly set out in ‘Document Type Definition’ (DTD)

XML in Healthcare industry
XML plays an important role in Healthcare industry as there are needs to store and share huge amount of various kinds of data. Boumphrey and Harrison (2000) say that:

XML has taken the business world by storm, and has revolutionized their document management strategies. Although it is just beginning to appear on the radar screens of most health care executives, it is likely that it will have a similar effect on the healthcare industry.

Unlike HTML, one of the most significant aspects XML document has is that it offers us the information of content itself.

Session4 Images and Graphics

Raster and Vector
Computers have two different ways to represent graphic information such as photographs, diagrams, illustrations, maps and charts.
The first one is raster which is grid based information. Information is stored in a sequence of square pixels. The other one is vector data which store and manipulate information defined with a series of point and boundaries. In both ways, geometric information is stored and manipulated numerically. One of the most important differences between raster information and vector information is that vector images never become blocky when they are zoomed and raster images may appear blocky as they are zoomed.

Raster geometry is represented by binary data which consist of two parts. The first part represent width and height of the raster image and the flowing part defines presence or absence of colors for each cells ( In the simple two color raster ). For example, 001001100010001 represent a figure below.


The first part of 001 001, means 3(width) by 3(height) and flowing 9 binary digits 100010001 demonstrate shape on the 3-by-3 raster geometry.
In order to manipulate more colorful data, there are two systems to represent colors. The RGB color system uses three basic colors which are red, green, blue. This is called additive model and used in TV and computer monitor. Cyan, magenta and yellow are used in the CMYK color system( K means black ). This is called subtractive model and used by print media.

Color data represented by using binary
Computers interpret color information by using binary data based on RGB color system. Different colors are represented by six figures. The first two figures represent the amount of red, the second pair of figures represent the amount of green and the last two figures represent the amount of blue. For instance, red is represented #FF0000. Orange which consist of a lot of red, some green and a few blue is represented #FF6633.

Session3 Internet/WWW

The Internet and World Wide Web
The Internet has revolutionized many aspects of our daily lives. It has changed the way we communicate and gain information.
The Internet is an infrastructure that has developed in 1960’s by American military as an electronic communication technology. By using the Internet, We can share information, data, knowledge and files. A network that connect individual computers in same environment and allows them to share resources is called Local Area Network or LAN. Connection between LANs create wider network and this is know as WAN. The Internet is a world wide network which is organized by these local or wide area networks.
World Wide Web is one of the services which is available over the Internet. While it has developed in 1990’s as a service that allows people in academia, it has become more common and widely used among ordinary people as it allows them to exchange many kinds of data.

Server computer and Client computer
There are two types of computers; one is server computers which are high powered computers. They receive and process request from client computers. Other one is client computers which send request and receive result. Server computer is run by a program called HTTP deamon which enable them to process requests that have been made by client machines and send information to them. Client computers use web browsers such as FireFox and Internet explore to send request to server computers.

HTML
Hypertext Mark-up Language or HTML is a set of special tags that allows users to identify the structure of web pages.　The important point is that HTML is designed to control only structure (and the presentation of a web page is controlled by CSS). From this point of view, some tags such as em, hr and br might not be eligible to be used as HTML tag.

activity in practical lab
I set up a web site on my student home page at City

Session2 Text/HTML

Bits, bytes and binary
When we count and calculate the number by using ten digits which include 0 1 2 3 4 5 6 7 8 9 to express quantity of the number. This is called the base 10 number system. We can interpret the combination of digits such as 27 or 365 or 2009 and can understand which combination is smaller and which is greater. However, there is no reason why the base ten number system is adopted in the way human count. Possibly it can be said that because humans have 10 fingers. Unlike humans, computers use the base two number system which has only two symbols, 0 or 1 to store data. Computers process and manage information by using the base two system. This is called binary system. Computers use a series of digits to interpret and transmit digital information and each of these digits is known as bits (binary digit). Two bits, for instance, it can express four different quantities; 00, 01, 10, 11 meaning 0, 1, 2, 3 respectively. 8 bits are especially known as bytes which can represent 256 different values. In addition to numeric data, computers can store and manage textual information by using alphabetical coding scheme called ASCII (the American Standard Code for Information Interchange and pronounced as-key). ASCII is used to interpret English alphabet letters (A-Z, a-z), numbers (0123456789) and other characters such as, !, @, $, %, &, which are commonly appear in keyboard of our computer.

Meta data and Mark-up
Data about data is called meta data. For example, additional context about main contents of document such as author’s detail, year and journal are represented as meta data. Meta data is added by using mark-up code which is tag with angle brackets.