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Uniprocessor Computers
Published in Vivek Kale, Parallel Computing Architectures and APIs, 2019
Input/output (I/O) devices: The primary input devices are The keyboard looks similar to that of a typewriter, with the addition of number keys and several additional keys that control computer-specific tasks.The mouse is useful in manipulating objects depicted on the screen.The microphone is useful in audio input in the form of verbal commands, dictation, and so on.The primary output devices are The monitor is a display device that forms an image by converting electrical signals from the computer into points of colored light on the screen. Its functioning is very similar to a television picture tube, but it has a much higher resolution so that a user sitting at close quarters can clearly see computer-generated data such as text and images.Printer.Speakers.
A Brief History of Video and Video Transmission
Published in David R. Goff, Kimberly Hansen, Michelle K. Stull, Fiber Optic Video Transmission, 2013
David R. Goff, Kimberly Hansen, Michelle K. Stull
The aspect ratio, which relates to the size of the screen, may be 16:9 for wide screen HDTV or 4:3, the aspect ratio used in current television sets and computer monitors. The digital domain simplifies the conversion of transmission formats and employs digital compression techniques, adding to the advantage of DTV standards. The HDTV standard allows for the clearest ever television transmission and reception, but the relatively high cost of an HDTV television currently prevents it from becoming as widely accepted as DTV. The FCC adopted this new digital standard in December 1996. Shortly thereafter, the FCC mandated that by 2006, all TV stations in the U.S. will be phased out or converted over to DTV stations broadcasting on newly assigned channels. At the same time, the freed space of the RF spectrum will be reassigned to other communications services such as wireless telephone transmission. By the end of 2001, more than 200 television stations had already added digital broadcast to their existing analog broadcast. Today networks broadcast most major network television shows using the HDTV standard, but local television stations and cable providers still broadcast NTSC standard video to the end user. But as with all new technologies, mass production will decrease the cost of HDTV televisions, making this technology as commonplace in the future as NTSC is today.
Medical Image Processing Environment
Published in Jiří Jan, Medical Image Processing, Reconstruction and Analysis, 2019
Another important monitor property is screen uniformity, in contrast transfer, basic brightness, and imaging properties (local point-spread function (PSF)). While the center of the image on a CRT may be of a high quality, imaging properties always deteriorate more or less toward margins, namely due to defocusing of the electron beams and worse convergence of R, G, and B beams. The uniformity of phosphors is usually very good. The LCD and OLED monitors do not suffer with imaging deterioration toward the borders; absolute pixel accuracy and focusing are maintained equally perfectly during the whole service life, as given by the principle. However, LCD monitors still suffer with a low viewing angle: they provide good contrast only when they are looked at perpendicularly. A deviation from this viewing angle leads at least to the darkening of the image and change of contrast, which may be visible on greater LCD monitors at margins even when they are looked at perpendicularly but from a close proximity. A different viewing angle may cause the image to change the contrast completely, perhaps reversing it, as well as a complete color distortion. This is particularly disturbing when more than one person should evaluate an image at a time. This property is improving gradually, and the best monitors can now be viewed well from a relatively wide angle (say ±50° from the perpendicular direction). In this respect, CRT monitors are better; their screens are practically cosine radiators and are thus visible from each angle with the same brightness, contrast, and colors. High-quality OLED monitors may be similar.
When Preschoolers Use Tablets: The Effect of Educational Serious Games on Children’s Attention Development
Published in International Journal of Human–Computer Interaction, 2021
Wen Liu, Liting Tan, Dan Huang, Nan Chen, Fang Liu
One hundred and seventy-one Chinese children aged three to four coming from an urban public preschool in Dalian, a northern city of China, participated in the study. Family income and parents’ education level from the school were in the average range of the city. The public schools’ enrollment prerequisites were applicants having normal sensory capacities and no history of psychopathologies. Primary classroom teachers delivered a letter to the children’s guardians about the study’s general purpose, along with a consent form regarding tablet app training at school and eye-tracking measurements. All parents signed the consent forms and returned them to the teachers. The Ethics Committee of Liaoning Normal University approved the study. During the pretest (before training), the 171 participants read an electronic picture book from a liquid crystal display (LCD) monitor. An eye tracker collected data on their eye movements. Six participants (2 three-year-old boys and 4 four-year-old girls) with low sampling rates were excluded from the study. The remaining 165 participants were divided into four groups – 43 three-year-old boys, 41 three-year-old girls, 40 four-year-old boys, and 41 four-year-old girls – on an excel sheet. Subsequently, the participants of these four groups were divided into the experimental and control groups.
Automated instrumentation for the determination of the high-temperature thermoelectric figure-of-merit
Published in Instrumentation Science & Technology, 2018
Ashutosh Patel, Sudhir K. Pandey
The heat loss is minimized by optimizing insulator cross-section and its thickness. This insulator block is supported by a rectangular brass bar, 6, using high temperature cement. Thin mica sheet, 7, is also used above the cold side copper block to insulate sample electrically. Good surface contact between sample and copper block is ensured by screwing threaded stainless steel (SS) rod, 8. The round tip of this SS rod ensures self-aligning of the cold side copper block over the sample surface and maintains almost constant pressure throughout the cross section of the sample. Another rectangular brass bar, 9, is used to hold the SS rod. Both rectangular brass bars have been fixed over two separate SS rods, 10, supported by the SS flange. PT-100 RTD is connected to the electrical connector to monitor the vacuum chamber temperature. The temperature of the measurement area during measurement is fixed at 300 K. A stainless-steel flange with sample holder assembly are put over the vacuum chamber, which is connected to the vacuum pump. Rotary vacuum pump is used to create a vacuum inside the chamber upto a level of ∼8 × 10−3 mbar.
Visual search tasks: measurement of dynamic visual lobe and relationship with display movement velocity
Published in Ergonomics, 2018
Lin-dong Yang, Rui-feng Yu, Xue-lian Lin, Ya-qing Xie, Liang Ma
The experiment was conducted using a DELL Vostro 5450-R1448 computer. The resolution of its 23.8-inch liquid crystal display monitor was 1920 pixels × 1080 pixels, and the refresh frequency was 60 Hz. A total of 191 ‘×’ as distractors and 1 ‘○’ as the target were located at the intersection points of 8 evenly spaced concentric circles and 24 regularly spaced meridians. The size of the dot, the distractors and the target was 0.7 radian, both horizontally and vertically. The distance of adjacent items on the same meridian was 20 pixels. The stimulus exposure time was 250 ms because a single-eye pause had an average duration of 200–300 ms (Megaw 1981). The target was randomly located in any position of the intersection points in each trial. Four trial rounds were used for each position. The participants were asked to sit on a height-adjustable chair. Then, they rested their heads on an adjustable chin rest to limit head movements. The chair and chin rest were adjusted to ensure that the distance between the screen and the eyes of the participants was 600 mm, and that the eyes were at the same height as the centre of the screen.