HCL detection in machine learning process .pptx
- 1. Chapter 3 Computer in HCI
- 2. The Computer • A computer system is made up of various elements each of these elements affects the interaction • input devices – text entry and pointing • output devices – screen (small & large), digital paper • virtual reality – special interaction and display devices • physical interaction – e.g. sound, haptic, bio-sensing • paper – as output (print) and input (scan) • memory – RAM & permanent media, capacity & access • processing – speed of processing, networks
- 3. Interacting with computers to understand human–computer interaction … need to understand computers! what goes in and out devices, paper, sensors, etc. what can it do? memory, processing, networks
- 4. Interactivity • Interaction (with or without computer) is a process of information transfer. • The diversity of devices reflects the fact that there are many different types of data that may be entered into and obtained from a system, as there are many different users. • In the early days, batch processing was common: a large mass of information was dumped into and processed by the computer. • Nowadays, computers respond within milliseconds and computer systems are integrated in many different devices.
- 5. Input Devices – Text entry devices • Keyboard • The vast majority of keyboards have a standardized layout, known by the first six letters on the top row: QWERTY. • The non-alphanumeric keys are not standardized. • This layout is not optimal for typing, but dates from the time of mechanical limitations of the typewriter.
- 6. Cont.. • Today, the keys can also be arranged in alphabetic order (the alphabetic keyboard), but this does not improve typing performance.
- 7. Chord keyboards • On chord keyboards, only a few keys are used. • Letters are produces pressing multiple keys at once. • They are smaller than conventional keyboards and have a short learning time.
- 8. Phone pad and T9 entry • The numeric keys on a cellphone can be pressed more than once to enter letters. • Most phones have 2 keypad modes: a numeric and an alphabetic mode. • Most phones have additional modes for entering (initial) capitals.
- 9. Cont.. • On modern phones you can also find the T9 algorithm. • This uses a large dictionary to disambiguate words by typing the relevant letters keys once.
- 10. Handwriting recognition • Text can be input into the computer, using a pen and a digesting tablet – natural interaction • Technical problems: – capturing all useful information - stroke path, pressure, etc. in a natural manner – segmenting joined up writing into individual letters – interpreting individual letters – Coping with different styles of handwriting • Used in PDAs, and tablet computers … … leave the keyboard on the desk!
- 11. Speech recognition • Improving rapidly • Most successful when: – single user – initial training and learns individualities – limited vocabulary systems • Problems with – external noise interfering – imprecision of pronunciation – large vocabularies – different speakers • Helps user who are visual disabled.
- 12. Numeric keypads • For entering numbers quickly: – calculator, PC keyboard • Widely used for telephones • Has two different layouts 4 5 6 7 8 9 * 0 # 1 2 3 4 5 6 1 2 3 0 . = 7 8 9 telephone calculator
- 13. Input Devices : positioning, pointing and drawing • The mouse • The mouse is an indirect input device, because a transformation is required to map from the horizontal nature of the desktop to the vertical alignment of the screen. • Invented in 1964 by Engelbart, his mouse used 2 wheels that slid across the desktop and transmitted x; y-coordinates to the computer. • There have been experiments with foot-controlled mice.
- 14. Touchpad • Touchpads are touch-sensitive tablets, operated by sliding the finger over it and are mostly used in notebook computers. • Performance can be increased using accelerators.
- 15. Trackball and thumbwheel • A trackball is an upside-down mouse: instead of moving the device itself, the ball is rolled to move the cursor. • Thumb-wheels (in 2 dimensions) offer less usability because they can only manipulate the horizontal and vertical movement of the cursor.
- 16. Cont.. • 1-dimensional thumbwheels are often included on the normal mice the enhance the scrolling.
- 17. Joystick and keyboard nipple • There are two types of joysticks: absolute sticks, in which the position of the cursor corresponds to the position of the joystick in its base. and • isometric sticks, in which the pressure on the stick (in a certain direction) controls the velocity of the cursor in that direction. • Keyboard nipples are tiny joysticks that are sometimes used on notebook computers.
- 18. Other input device • Touch-sensitive screens (touchscreens) • Stylus and light pen • Digitizing tablet • Eye gaze • Cursor keys and discrete positioning
- 19. Output Devices - Display devices • Bitmap displays, resolution and color • A bitmap-base means that the display is made of a fixed number of dots or pixels in a rectangular grid. • The color or intensity at each pixel is held by the computer's video card. • The more bits per pixel, the more colors/intensities are possible.
- 20. Technologies • In a CRT-monitor a stream of electrons is emitted from an electron gun, which is than focused and directed by magnetic . • In LCD.s a thin layer of liquid crystals is sandwiched between two glass plates. • External light passes through the top plate and is polarized. • This passes through the crystal and is reflected back to the user's eye by the bottom plate.
- 21. Digital paper • Thin flexible material that can be written to electronically, but keeps it's contents when removed from the power supply.
- 22. Devices for virtual reality and 3D interaction • Positioning in 3D : • Changing from 2D to VR does not mean going to 3 degrees of freedom, but (sometimes) to 6, because except for moving in 3 dimensions, you can also roll, turn, twist etc. • Humans can use a 3D-environment with a 2D-device (mouse). • The human mind is therefore capable of handling multiple degrees of indirection.
- 23. 3D displays • 3D can be displayed on normal screens using shadows, depth etc. • It is also possible to generate the natural stereoscopic images for both eye positions and have them delivered to eyes using a VR-helmed. • Finally, users can enter a VR cave, where the VR world is projected around them. • If the VR-system performances too slow, and there is a delay between movement and image, disorientation and sickness may occur.
- 24. Physical controls, sensors and special devices • Special displays : • Except for CRT and LCD, there are numerous other display devices, e.g. LED.s, gangs, dials and head- up displays.
- 25. Touch, feel and smell • Force feedback gives different amounts of resistance to an input device depending on the state of the virtual operation. • Haptic devices are various forms of force, resistance and texture influencing our physical senses.
- 26. Environment and bio-sensing • There are many sensors in our environment monitoring our behavior. • Their measurements range from temperature and movement to the user's emotional state.
- 27. Paper: printing • The most common printers nowadays are dot-based. • In order of increasing resolution, familiar types are dot-matrix printers, ink-jet printers and laser printers. • Some printers print ASCII-characters and bitmaps by itself. • Many more complex documents are translated into suitable bitmaps by the computer. • More sophisticated printers can accept a page description language, e.g. PostScript.
- 28. Scanners and optical character recognition • Scanners produce a bitmap image from a hard original and can, using optical character recognition, transfer a page of text directly into a txt-file. • There are 2 kinds of scanners: flat-bed (as in a copier machine) and hand-held (as in a fax machine, however the scanner has to be manually pulled over the paper). • Scanners shine a beam of light at the page and record the intensity and color of the reflection. • The resolution of the scanner can differ highly between different types.
- 29. Memory- RAM and short-term memory (STM) • Most current active information is held in the random access memory (RAM). • RAM is volatile: contents are lost when the power is turned off. • However, there are more expensive or low-power consuming memory techniques that can hold their contents when the power is off.
- 30. Disks and long-term memory (LTM) • There are 2 main techniques used in disks: magnetic disks (floppy, hard disk, tape) and optical disks. (CD-ROM/DVD). • In comparison to RAM, the computers LTM is rather slow.
- 31. Understanding speed and capacity • The capacity of RAM is limited and therefore multitask-systems tend to swap background- running programs from RAM to the hard disk. • When the program is fully activated it has to be swapped back, which can cause delays (von Neumann bottleneck).
- 32. Compression • Compression techniques can be used to reduce the amount of storage required for text, bitmaps and video. • In text, logical contractions in the sentence can be replaced by a short code. • In video, differences between frames can be recorded instead of the whole frames.
- 33. Methods of access • Standard database access by special key fields with an associated index. • The user has to know the key before the system can find the information. • Indices on databases are limited due to the storage costs, privacy and security. • The user's mistakes in searching can be compensated by using forgiving systems, for example by matching a key to a database index which corresponds closely.
- 34. Processing and networks • Effects of finite processor speed • The processing speed of an interactive system can effect the user by being too slow (which can be avoided by using buffers) or too fast. • The faults can be functional, in which the program does the wrong action. • Slow responses from the system can also cause the so called cursor tracking and icon wars. • If the system is too fast, the user will not have enough time to interpret the system's output.
- 35. Limitations on interactive performance • Several factors that can limit the speed of an interactive system. They can be: – Computation bound: Make sure the user has an indication of the system's progress. – Storage channel bound: Select the best fitting kind of memory and access technique. – Graphics bound: The actual time of graphic operations can differ much from the estimates. – Network capacity
- 36. Network computing • Networked systems have an effect on interactivity, because the large distances may cause a noticeable delay in response from the system. • The actions of other users may also influence your own interaction with the connected computers.