Information Technology

  Top 10 Information Technology (IT) Companies in World 2019  1. Microsoft Corporation Microsoft Corporation is headquartered in Redmond, Washington, and is one of the largest companies in the world. Image: pixabay The products like Microsoft Windows, Microsoft Office, and Internet Explorer etc is being used by almost by almost every professional in the world. Microsoft was founded by Bill Gates and Paul Allen on 4, April, 1975, and it has expanded its market share by diversifying its services from operating system market to other various software products. It also took advantage of inorganic growth i.e. improve its revenue by acquiring no. of companies. Lastly Microsoft has acquired Linkedin which is considered to be largest acquisition for 26.2 billion dollars in 2016 and also it has acquired skype technologies for 8.5 billion dollars in the year 2011. There is a new paradigm shift in technology with the rapidly evolving environment and Microsoft is trying to le...

Differentiate between DDA Algorithm and Bresenham's Line Algorithm: DDA Algorithm Bresenham's Line Algorithm 1. DDA Algorithm use floating point, i.e., Real Arithmetic. 1. Bresenham's Line Algorithm use fixed point, i.e., Integer Arithmetic 2. DDA Algorithms uses multiplication & division its operation 2.Bresenham's Line Algorithm uses only subtraction and addition its operation 3. DDA Algorithm is slowly than Bresenham's Line Algorithm in line drawing because it uses real arithmetic (Floating Point operation) 3. Bresenham's Algorithm is faster than DDA Algorithm in line because it involves only addition & subtraction in its calculation and uses only integer arithmetic. 4. DDA Algorithm is not accurate and efficient as Bresenham's Line Algorithm. 4. Bresenham's Line Algorithm is more accurate and efficient at DDA Algorithm. 5.DDA Algorithm can draw circle and curves but are not accurate as Bresenham's Line...

Scan Converting a Straight Line A straight line may be defined by two endpoints & an equation. In fig the two endpoints are described by (x 1 ,y 1 ) and (x 2 ,y 2 ). The equation of the line is used to determine the x, y coordinates of all the points that lie between these two endpoints. Using the equation of a straight line, y = mx + b where m = & b = the y interrupt, we can find values of y by incrementing x from x =x 1 , to x = x 2 . By scan-converting these calculated x, y values, we represent the line as a sequence of pixels. Properties of Good Line Drawing Algorithm: 1. Line should appear Straight: We must appropriate the line by choosing addressable points close to it. If we choose well, the line will appear straight, if not, we shall produce crossed lines. The lines must be generated parallel or at 45° to the x and y-axes. Other lines cause a problem: a line segment through it starts and finishes at addressable points, may happen to pass through no an...

Scan Converting a Point Each pixel on the graphics display does not represent a mathematical point. Instead, it means a region which theoretically can contain an infinite number of points. Scan-Converting a point involves illuminating the pixel that contains the point. Example: Display coordinates points as shown in fig would both be represented by pixel (2, 1). In general, a point p (x, y) is represented by the integer part of x & the integer part of y that is pixels [(INT (x), INT (y).

Scan Conversion Definition It is a process of representing graphics objects a collection of pixels. The graphics objects are continuous. The pixels used are discrete. Each pixel can have either on or off state. The circuitry of the video display device of the computer is capable of converting binary values (0, 1) into a pixel on and pixel off information. 0 is represented by pixel off. 1 is represented using pixel on. Using this ability graphics computer represent picture having discrete dots. Any model of graphics can be reproduced with a dense matrix of dots or points. Most human beings think graphics objects as points, lines, circles, ellipses. For generating graphical object, many algorithms have been developed. Advantage of developing algorithms for scan conversion Algorithms can generate graphics objects at a faster rate. Using algorithms memory can be used efficiently. Algorithms can develop a higher level of graphical objects. Examples of objects which can ...

Plotters Plotters are a special type of output device. It is suitable for applications: Architectural plan of the building. CAD applications like the design of mechanical components of aircraft. Many engineering applications. Advantage: It can produce high-quality output on large sheets. It is used to provide the high precision drawing. It can produce graphics of various sizes. The speed of producing output is high. Drum Plotter: It consists of a drum. Paper on which design is made is kept on the drum. The drum can rotate in both directions. Plotters comprised of one or more pen and penholders. The holders are mounted perpendicular to drum surface. The pens are kept in the holder, which can move left to the right as well as right to the left. The graph plotting program controls the movement of pen and drum. Flatbed Plotter: It is used to draw complex design and graphs, charts. The Flatbed plotter can be kept over the table. The plotter consists of pen and hold...

Output Devices It is an electromechanical device, which accepts data from a computer and translates them into form understand by users. Following are Output Devices: Printers Plotters Printers: Printer is the most important output device, which is used to print data on paper. Types of Printers: There are many types of printers which are classified on various criteria as shown in fig: 1. Impact Printers: The printers that print the characters by striking against the ribbon and onto the papers are known as Impact Printers. These Printers are of two types: Character Printers Line Printers 2. Non-Impact Printers: The printers that print the characters without striking against the ribbon and onto the papers are called Non-Impact Printers. These printers print a complete page at a time, therefore, also known as Page Printers. Page Printers are of two types: Laser Printers Inkjet Printers Dot Matrix Printers: Dot matrix has printed in the form of do...

Light Pen Light Pen (similar to the pen) is a pointing device which is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small tube. When its tip is moved over the monitor screen, and pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signals to the CPU. Uses: Light Pens can be used as input coordinate positions by providing necessary arrangements. If background color or intensity, a light pen can be used as a locator. It is used as a standard pick device with many graphics system. It can be used as stroke input devices. It can be used as valuators Digitizers: The digitizer is an operator input device, which contains a large, smooth board (the appearance is similar to the mechanical drawing board) & an electronic tracking device, which can be changed over the surface to follow existing lines. The electronic tracking dev...

Trackball It is a pointing device. It is similar to a mouse. This is mainly used in notebook or laptop computer, instead of a mouse. This is a ball which is half inserted, and by changing fingers on the ball, the pointer can be moved. Advantage: Trackball is stationary, so it does not require much space to use it. Compact Size Spaceball: It is similar to trackball, but it can move in six directions where trackball can move in two directions only. The movement is recorded by the strain gauge. Strain gauge is applied with pressure. It can be pushed and pulled in various directions. The ball has a diameter around 7.5 cm. The ball is mounted in the base using rollers. One-third of the ball is an inside box, the rest is outside. Applications: It is used for three-dimensional positioning of the object. It is used to select various functions in the field of virtual reality. It is applicable in CAD applications. Animation is also done using spaceball. It is used in the...

Input Devices The Input Devices are the hardware that is used to transfer transfers input to the computer. The data can be in the form of text, graphics, sound, and text. Output device display data from the memory of the computer. Output can be text, numeric data, line, polygon, and other objects. These Devices include: Keyboard Mouse Trackball Spaceball Joystick Light Pen Digitizer Touch Panels Voice Recognition Image Scanner Keyboard: The most commonly used input device is a keyboard. The data is entered by pressing the set of keys. All keys are labeled. A keyboard with 101 keys is called a QWERTY keyboard. The keyboard has alphabetic as well as numeric keys. Some special keys are also available. Numeric Keys: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Alphabetic keys: a to z (lower case), A to Z (upper case) Special Control keys: Ctrl, Shift, Alt Special Symbol Keys: ; , " ? @ ~ ? : Cursor Control Keys: ↑ → ← ↓ Function Keys: F1 F2 F3....F9. Nume...

Flat Panel Display: The Flat-Panel display refers to a class of video devices that have reduced volume, weight and power requirement compare to CRT. Example: Small T.V. monitor, calculator, pocket video games, laptop computers, an advertisement board in elevator. 1. Emissive Display: The emissive displays are devices that convert electrical energy into light. Examples are Plasma Panel, thin film electroluminescent display and LED (Light Emitting Diodes). 2. Non-Emissive Display: The Non-Emissive displays use optical effects to convert sunlight or light from some other source into graphics patterns. Examples are LCD (Liquid Crystal Device). Plasma Panel Display: Plasma-Panels are also called as Gas-Discharge Display. It consists of an array of small lights. Lights are fluorescent in nature. The essential components of the plasma-panel display are: Cathode: It consists of fine wires. It delivers negative voltage to gas cells. The voltage is released along with th...

Color CRT Monitors: The CRT Monitor display by using a combination of phosphors. The phosphors are different colors. There are two popular approaches for producing color displays with a CRT are: Beam Penetration Method Shadow-Mask Method 1. Beam Penetration Method: The Beam-Penetration method has been used with random-scan monitors. In this method, the CRT screen is coated with two layers of phosphor, red and green and the displayed color depends on how far the electron beam penetrates the phosphor layers. This method produces four colors only, red, green, orange and yellow. A beam of slow electrons excites the outer red layer only; hence screen shows red color only. A beam of high-speed electrons excites the inner green layer. Thus screen shows a green color. Advantages: Inexpensive Disadvantages: Only four colors are possible Quality of pictures is not as good as with another method. 2. Shadow-Mask Method: Shadow Mask Method is commonly used in Raster-Scan...