Exam Time for IT. Ч.1. Практикум

Topic 3. Web design

Web design is a process of conceptualization, planning, modeling, and execution of electronic media content delivery via Internet in the form of technologies (such as markup languages) suitable for interpretation and display by a web browser or other web-based graphical user interfaces (GUIs).

The intent of web design is to create a web site (a collection of electronic files residing on one or more web servers) that presents content (including interactive features or interfaces) to the end user in the form of web pages once requested. Such elements as text, forms, and bit-mapped images (GIFs, JPEGs, PNGs) can be placed on the page using HTML, XHTML, or XML tags. Displaying more complex media (vector graphics, animations, videos, sounds) usually requires plug-ins such as Flash, QuickTime, Java run-time environment, etc. Plug-ins are also embedded into web pages by using HTML or XHTML tags.

Typically web pages are classified as static or dynamic. Static pages don’t change content and layout with every request unless a human (web master or programmer) manually updates the page. Dynamic pages adapt their content and/or appearance depending on the end-user’s input or interaction or changes in the computing environment (user, time, database modifications, etc.) Content can be changed on the client side (end-user’s computer) by using client-side scripting languages (JavaScript, JScript, Actionscript, media players and PDF reader plug-ins, etc.) to alter DOM elements (DHTML). Dynamic content is often compiled on the server utilizing server-side scripting languages (PHP, ASP, Perl, Coldfusion, JSP, Python, etc.). Both approaches are usually used in complex applications.

With growing specialization within communication design and information technology fields, there is a strong tendency to draw a clear line between web design specifically for web pages and web development for the overall logistics of all web-based services.

Web Site Design.

A web site is a collection of information about a particular topic or subject. Designing a web site is defined as the arrangement and creation of web pages that in turn make up a web site. A web page consists of information for which the web site is developed. A web site might be compared to a book, where each page of the book is a web page.

There are many aspects (design concerns) in this process, and due to the rapid development of the Internet, new aspects may emerge. For non-commercial web sites, the goals may vary depending on the desired exposure and response. For typical commercial web sites, the basic aspects of design are:

the content: the substance, and information on the site should be relevant to the site and should target the area of the public that the website is concerned with.

the usability: the site should be user-friendly, with the interface and navigation simple and reliable.

the appearance: the graphics and text should include a single style that flows throughout, to show consistency. The style should be professional, appealing and relevant.

the visibility: the site must also be easy to find via most, if not all, major search engines and advertisement media.

A web site typically consists of text and images. The first page of a web site is known as the Home page or Index. Some web sites use what is commonly called a Splash Page. Splash pages might include a welcome message, language or region selection, or disclaimer. Each web page within a web site is an HTML file which has its own URL. After each web page is created, they are typically linked together using a navigation menu composed of hyperlinks. Faster browsing speeds have led to shorter attention spans and more demanding online visitors and this has resulted in less use of Splash Pages, particularly where commercial web sites are concerned.

Once a web site is completed, it must be published or uploaded in order to be viewable to the public over the internet. This may be done using an FTP client. Once published, the web

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master may use a variety of techniques to increase the traffic, or hits, that the web site receives. This may include submitting the web site to a search engine such as Google or Yahoo, exchanging links with other web sites, creating affiliations with similar web sites, etc.

Multidisciplinary Requirements.

Web site design crosses multiple disciplines of information systems, information technology and communication design. The web site is an information system whose components are sometimes classified as front-end and back-end. The observable content (e.g. page layout, user interface, graphics, text, audio) is known as the front-end. The back-end comprises the organization and efficiency of the source code, invisible scripted functions, and the server-side components that process the output from the front-end. Depending on the size of a Web development project, it may be carried out by a multi-skilled individual (sometimes called a web master), or a project manager may oversee collaborative design between group members with specialized skills.

Accessible Web Design.

To be accessible, web pages and sites must conform to certain accessibility principles. These can be grouped into the following main areas:

use semantic markup that provides a meaningful structure to the document (i.e. web page); (Semantic markup also refers to semantically organizing the web page structure and publishing web services description accordingly so that they can be recognized by other web services on different web pages. Standards for semantic web are set by IEEE.);

use a valid markup language that conforms to a published DTD or Schema;

provide text equivalents for any non-text components (e.g. images, multimedia);

use hyperlinks that make sense when read out of context;

don’t use frames;

use CSS rather than HTML Tables for layout;

author the page so that when the source code is read line-by-line by user agents (such as a screen readers) it remains intelligible.

However, W3C permits an exception where tables for layout either make sense when linearized or an alternate version (perhaps linearized) is made available. Website accessibility is also changing as it is impacted by Content Management Systems that allow changes to be made to webpages without the need of obtaining programming language knowledge.

Website Planning.

Before creating and uploading a website, it is important to take the time to plan exactly what is needed in the website. Thoroughly considering the audience or target market, as well as defining the purpose and deciding what content will be developed are extremely important.

Purpose.

It is essential to define the purpose of the website as one of the first steps in the planning process. A purpose statement should show focus based on what the website will accomplish and what the users will get from it. A clearly defined purpose will help the rest of the planning process as the audience is identified and the content of the site is developed. Setting short and long term goals for the website will help make the purpose clear and plan for the future when expansion, modification, and improvement will take place. Also, goal-setting practices and measurable objectives should be identified to track the progress of the site and determine success.

Audience.

Defining the audience is a key step in the website planning process. The audience is the group of people who are expected to visit your website — the market being targeted. These people will be viewing the website for a specific reason and it is important to know exactly what they are looking for when they visit the site. A clearly defined purpose or goal of the site as well as an understanding of what visitors want to do or feel when they come to your site will help to

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identify the target audience. Upon considering who is most likely to need or use the content, a list of characteristics common to the users such as:

Audience Characteristics

Information Preferences

Computer Specifications

Web Experience

Taking into account the characteristics of the audience will allow an effective website to be created that will deliver the desired content to the target audience.

Content.

Content evaluation and organization requires that the purpose of the website be clearly defined. Collecting a list of the necessary content then organizing it according to the audience’s needs is a key step in website planning. In the process of gathering the content being offered, any items that do not support the defined purpose or accomplish target audience objectives should be removed. It is a good idea to test the content and purpose on a focus group and compare the offerings to the audience needs. The next step is to organize the basic information structure by categorizing the content and organizing it according to user needs. Each category should be named with a concise and descriptive title that will become a link on the website. Planning for the site’s content ensures that the wants or needs of the target audience and the purpose of the site will be fulfilled.

Compatibility and Restrictions.

Because of the market share of modern browsers (depending on your target market), the compatibility of your website with the viewers is restricted. For instance, a website that is designed for the majority of websurfers will be limited to the use of valid XHTML 1.0 Strict or older, Cascading Style Sheets Level 1, and 1024x768 display resolution. This is because Internet Explorer is not fully W3C standards compliant with the modularity of XHTML 1.1 and the majority of CSS beyond 1. A target market of more alternative browser (e.g. Firefox and Opera) users allow for more W3C compliance and thus a greater range of options for a web designer.

Another restriction on webpage design is the use of different Image file formats. The majority of users can support GIF, JPEG, and PNG (with restrictions). Again Internet Explorer is the major restriction here, not fully supporting PNG’s advanced transparency features, resulting in the GIF format still being the most widely used graphic file format for transparent images. Many website incompatibilities go unnoticed by the designer and unreported by the users. The only way to be certain a website will work on a particular platform is to test it on that platform.

Questions for self-check:

What kind of a process is web design? Give general characteristics.

What is web design aimed at?

How are web pages classified?

What is a web site? What is it compared to?

What are the steps of a web site creating?

What classification of web site components is proposed?

What points should be considered before creating and uploading a website? Cover each one.

Exercises:

1. Give Russian equivalents of the following words and expressions:

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Topic 4. Computer software

Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some task on a computer system. The term includes application software such as word processors which perform productive tasks for users, system software such as operating systems, which interface with hardware to provide the necessary services for application software, and middleware which controls and co-ordinates distributed systems.

The term «software» is sometimes used in a broader context to describe any electronic media content which embodies expressions of ideas such as film, tapes, records, etc.

Computer software is so called to contrast with computer hardware, which encompasses the physical interconnections and devices required to store and execute (or run) the software. In computers, software is loaded into RAM and executed in the central processing unit. At the lowest level, software consists of a machine language specific to an individual processor. A machine language consists of groups of binary values signifying processor instructions (object code), which change the state of the computer from its preceding state. Software is an ordered sequence of instructions for changing the state of the computer hardware in a particular sequence. It is usually written in high-level programming languages that are easier and more efficient for humans to use (closer to natural language) than machine language. High-level languages are compiled or interpreted into machine language object code. Software may also be written in an assembly language, essentially, a mnemonic representation of a machine language using a natural language alphabet. Assembly language must be assembled into object code via an assembler.

The term «software» was first used in this sense by John W. Tukey in 1958. In computer science and software engineering, computer software is all computer programs. The concept of reading different sequences of instructions into the memory of a device to control computations was invented by Charles Babbage as part of his difference engine. The theory that is the basis for most modem software was first proposed by Alan Turing in his 1935 essay ‘Computable Numbers’.

Types.

Practical computer systems divide software systems into three major classes: system software, programming software and application software, although the distinction is arbitrary, and often blurred.

System software helps run the computer hardware and computer system. It includes operating systems, device drivers, diagnostic tools, servers, windowing systems, utilities and more. The purpose of system software is to insulate the applications programmer as much as possible from the details of the particular computer complex being used, especially memory and other hardware features, and such accessory devices as communications, printers, readers, displays, keyboards, etc.

Programming software usually provides tools to assist a programmer in writing computer programs and software using different programming languages in a more convenient way. The tools include text editors, compilers, interpreters, linkers, debuggers, and so on. An Integrated development environment (IDE) merges those tools into a software bundle, and a programmer may not need to type multiple commands for compiling, interpreter, debugging, tracing, and etc., because the IDE usually has an advanced graphical user interface, or GUI.

Application software allows end users to accomplish one or more specific (non-computer related) tasks. Typical applications include industrial automation, business software, educational software, medical software, databases, and computer games. Businesses are probably the biggest users of application software, but almost every field of human activity now uses some form of application software.

Program and Library.

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A program may not be sufficiently complete for execution by a computer. In particular, it may require additional software from a software library in order to be complete. Such a library may include software components used by stand-alone programs, but which cannot work on their own. Thus, programs may include standard routines that are common to many programs, extracted from these libraries. Libraries may also include ‘stand-alone’ programs which are activated by some computer event and/or perform some function (e.g., of computer

‘housekeeping’) but do not return data to their calling program. Libraries may be called by one to many other programs; programs may call zero to many other programs.

Three Layers.

Starting in the 1980s, application software has been sold in massproduced packages through retailers. Users often see things differently than programmers. People who use modern general purpose computers (as opposed to embedded systems, analog computers, supercomputers, etc.) usually see three layers of software performing a variety of tasks: platform, application, and user software.

Platform Software.

Platform includes the firmware, device drivers, an operating system, and typically a graphical user interface which, in total, allow a user to interact with the computer and its peripherals (associated equipment). Platform software often comes bundled with the computer. On a PC you will usually have the ability to change the platform software.

Application Software.

Application software or Applications are what most people think of when they think of software. Typical examples include office suites and video games. Application software is often purchased separately from computer hardware. Sometimes applications are bundled with the computer, but that does not change the fact that they run as independent applications. Applications are almost always independent programs from the operating system, though they are often tailored for specific platforms. Most users think of compilers, databases, and other

«system software» as applications.

User-Written Software.

User software tailors systems to meet the users specific needs. User software includes spreadsheet templates, word processor macros, scientific simulations, and scripts for graphics and animations. Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is. Depending on how competently the userwritten software has been integrated into purchased application packages, many users may not be aware of the distinction between the purchased packages, and what has been added by fellow coworkers.

Operation.

Computer software has to be «loaded» into the computer’s storage (such as a hard drive, memory, or RAM). Once the software is loaded, the computer is able to execute the software. Computers operate by executing the computer program. This involves passing instructions from the application software, through the system software, to the hardware which ultimately receives the instruction as machine code. Each instruction causes the computer to carry out an operation

— moving data, carrying out a computation, or altering the control flow of instructions.

Data movement is typically from one place in memory to another. Sometimes it involves moving data between memory and registers which enable high-speed data access in the CPU. Moving data, especially large amounts of it, can be costly. So, this is sometimes avoided by using «pointers» to data instead. Computations include simple operations such as incrementing the value of a variable data element. More complex computations may involve many operations and data elements together.

Instructions may be performed sequentially, conditionally, or iteratively. Sequential instructions are those operations that are performed one after another. Conditional instructions are performed such that different sets of instructions execute depending on the value(s) of some data. In some languages this is known as an «if» statement. Iterative instructions are performed

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repetitively and may depend on some data value. This is sometimes called a «loop.» Often, one instruction may «call» another set of instructions that are defined in some other program or module. When more than one computer processor is used, instructions may be executed simultaneously.

A simple example of the way software operates is what happens when a user selects an entry such as «Сору» from a menu. In this case, a conditional instruction is executed to copy text from data in a ‘document’ area residing in memory, perhaps to an intermediate storage area known as a ‘clipboard’ data area. If a different menu entry such as «Paste» is chosen, the software may execute the instructions to copy the text from the clipboard data area to a specific location in the same or another document in memory.

Depending on the application, even the example above could become complicated. The field of software engineering endeavors to manage the complexity of how software operates. This is especially true for software that operates in the context of a large or powerful computer system.

Currently, almost the only limitation on the use of computer software in applications is the ingenuity of the designer/programmer. Consequently, large areas of activities (such as playing grand master level chess) formerly assumed to be incapable of software simulation are now routinely programmed. The only area that has so far proved reasonably secure from software simulation is the realm of human art — especially, pleasing music and literature.

Questions for self-check:

Who was the term first used by?

How do computer hardware and software correlate?

What major classes are software systems divided into? Describe each one.

What does a library include?

How many layers of software do general purpose computers comprise? Characterize all of them.

How do computers operate?

What is almost the only limitation on the use of computer software? Why?

Exercises:

1. Give Russian equivalents of the following words and expressions:

suite; routine; clipboard; ingenuity; middleware; ordered sequence; retailer; debugger; template; arbitrary; stand-alone; iteratively; bundle; encompass; extract; insulate; paste; precede; endeavour; tailor

2.Find the word belonging to the given synonymic group among the words and word combinations from the previous exercise:

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3. Translate these words and word combinations into English:

предшествовать; произвольный, случайный; розничный торговец; многократно; связующее ПО; отделять; подпрограмма; автономный; охватывать; (программный) комплект; вставить; упорядоченная последовательность; извлекать; шаблон, трафарет; разрабатывать, адаптировать; буфер обмена; пытаться, стараться; отладчик; поставлять комплектно; изобретательность.

4.Say which of the following statements are true or false. Correct the false ones:

1.Computer software encompasses the physical interconnections and devices required to store and execute (or run) the program.

2.The purpose of system software is to insulate the applications programmer as much as possible from the details of the particular computer complex being used, especially memory and other hardware features, and such accessory devices as communications, printers, readers, displays, keyboards, etc.

3.Programming software allows end users to accomplish one or more specific (noncomputer related) tasks.

4.Libraries may include standard routines that are common to many programs.

5.Application software often comes bundled with the computer and you will usually have the ability to change it on a PC.

6.User software includes spreadsheet templates, word processor macros, scientific simulations, and scripts for graphics and animations.

7.Instructions may be performed sequentially, conditionally, or iteratively.

8.Iterative instructions are those operations that are performed one after another.

9.Conditional instructions are performed such that different sets of instructions execute depending on the value(s) of some data.

10.The only area that has so far proved reasonably secure from software simulation is the realm of human art — especially, pleasing music and literature.

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Topic 5. Computer hardware

Computer hardware is the physical part of a computer, including its digital circuitry, as distinguished from the computer software that executes within the hardware. The hardware of a computer is infrequently changed, in comparison with software and hardware data, which are

«soft» in the sense that they are readily created, modified or erased on the computer. Firmware is a special type of software that rarely, if ever, needs to be changed and so is stored on hardware devices such as read-only memory (ROM) where it is not readily changed (and is, therefore,

«firm» rather than just «soft»).

Most computer hardware is not seen by normal users. It is in embedded systems in automobiles, microwave ovens, electrocardiograph machines, compact disc players, and other devices. Personal computers, the computer hardware familiar to most people, form only a small minority of computers.

Typical PC hardware.

A typical personal computer consists of a case or chassis in a tower shape (desktop) and the following parts:

The CPU (Central Processing Unit), which is the ‘brain’ of the computer. It’s typically a square ceramic package plugged into the motherboard, with a large heat sink on top (and often a fan on top of that heat sink). All instructions the computer will process are processed by the

CPU. There are many «CPU architectures», each of which has its own characteristics and tradeoffs. The dominant CPU architectures used in personal computing are x86 and PowerPC. x86 is easily the most popular processor for this class of machine (the dominant manufacturers of x86 CPUs are Intel and AMD). The other architechtures are used, for istance, in workstations, servers or embedded systems CPUs, contain a small amount of static RAM (SRAM) called a cache. Some processors have two or three levels of cache, containing as much as several megabytes of memory.

Dual Core. Some of the new processors made by Intel and AMD are Dual core. The

Intel designation for dual core are «Pentium D», «Core Duo» and «Core 2 Duo» while AMD has its «Х2» series and «FX-бх». The core is where the data is processed and turned into commands directed at the rest of the computer. Having two cores increases the data flow into the processor and the command flow out of the processor potentially doubling the processing power, but the increased performance is only visible with multithreaded applications and heavy multitasking.

Hyper Threading. Hyper threading is a technology that uses one core but adds a virtual processor to an additional thread at the same time. Normally the processor carries out one task and then proceeds onto the next task. But with Hyper Threading the processor continually switches in-between each task as if to do them at the same time.

Case. Most modern computers have an «АТХ form factor» case in which АТХcompatible power supplies, Mainboards and Drives can be mounted. The Mini-ITX is much different in important ways unlike its relatives the Micro-ATX and the Flex-ATX. The mainboard size can be up to 170 mm x 170 mm which is smaller than the Flex and Micro-ATX can be. Usually at less than 100 watts, the Mini-ITX PSU is energy efficient. The Mini-ITX is also backward-compatible with the Flex/Micro-ATX models. During the 1980’s and 1990’s almost all cases were beige, even Apple’s Macintosh line. A few rare exceptions to this were black. Only recently have computer case designers realized that there was a worthwhile market for other colors and designs. This has led to all sorts of modifications to the basic design of a computer case. Now it is easy to find cases with transparent windows and glowing lights illuminating their insides.

Power Supply. All computers have some sort of power supply. This converts the supply voltage (AC 110 or 220V) to different voltages such as DC 5V, 12V and 3.3V. These are needed inside the computer system by nearly every component inside the computer. There will be a bunch of connectors coming off of the supply, called Molex connectors. They come in varying

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sizes, meant for different applications, such as the motherboard (usually the largest of the connectors), the hard and optical drives (a bunch of mediumsized connectors), as well as the floppy drive (a relatively small connector, also saw usage among videocards in 2004). As newer standards come out, the types of connectors have changed. Many power supplies now come with power connectors for Serial AT A hard drives. These are smaller and are «hot-swappable», meaning they can be removed and plugged in again without fear of data loss or electrical problems. The power supply also has an exhaust fan that is responsible for cooling the power supply, as well as providing a hot air exhaust for the entire case. Some power supplies have two fans to promote this effect. It is important to buy a power supply that can accommodate all of the components involved. Some may argue that it is the most important part of a computer, and therefore it is worth spending the money to get a decent one.

Motherboard. The Motherboard (also called Mainboard) is a large, thin, flat, rectangular fiberglass board (typically green) attached to the case. The Motherboard carries the CPU, the RAM, the chipset and the expansion slots (PCI, AGP — for graphics, ISA, etc.). The Motherboard also holds things like the BIOS (Basic Input Output System) and the CMOS Battery (a coin cell that keeps an embedded RAM in the motherboard -often NVRAMpowered to keep various settings in effect). Most modem motherboards have onboard sound and LAN controller, some of them even have on-board graphics. These are adequate for standard office work and system sounds. But dedicated sound and graphics cards plugged into the expansion slots offer much better quality and performance.

RAM. Random Access Memory (RAM) is a memory that the microprocessor uses to store data during processing. This memory is volatile (loses its contents at power-down). When a software application is launched, the executable program is loaded from hard drive to the RAM. The microprocessor supplies address into the RAM to read instructions and data from it. RAM is needed because hard drives are too slow to operate with the speed of a microprocessor.

AGP Cards. Most graphic cards produced from about 1998-2004 were AGP (Accelerated Graphics Port) cards. They are placed in a certain slot on the mainboard with an extra high data transfer rate. The interface was invented to keep the graphics card away from the PCI bus, which was starting to become too constrained for modern graphics cards. Every graphic card carries a graphic chip (GPU) and very fast DDR RAM for textures and 3D data. Their data buses have IX, 2X, 4X, and 8X speeds. The bus is 32-bit, much like PCI. GP slots are slightly shorter than PCI slots and often brown in color. A similar type of slot called AGP Pro is longer and has extra power leads to accommodate modem video cards. It didn’t really catch on in the mainstream market, and graphics card makers preferred to add an extra power connector to supply the power they needed.

PCI Cards. The Peripheral Component Interconnect, or PCI Standard (in practice almost always shortened to PCI), specifies a computer bus for attaching peripheral devices to a computer motherboard. These devices can take any one of the following forms: An integrated circuit fitted onto the motherboard itself, called a planar device in the PCI specification. An expansion card that fits into a socket. The PCI (Peripheral Component Interconnect) bus is the most popular internal interconnect for personal computers. They are usually white in color.

PCI Express Cards/Slots. The PCI Express standard was created to replace both AGP and PCI slots. Unlike previous PC expansion interfaces, rather than being a bus it is structured around point-to-point serial links called lanes. The reason is that the older PCI cards don’t transfer data quickly enough to keep up with modern day gaming, autocad and video editing software.

ISA Cards. Industry Standard Architecture (ISA) cards were the original PC extension cards. Originally running on an 8-bit bus, they ran on a 16bit bus as of 1984. Like PCI slots, they supported Plug-and-Play as of 1993 (prior to this, one had to set jumpers for IRQ interrupts and such). In comparison to PCI slots, they are rather long, and often black in color. They are not found on most computers built after 1999.

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