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Bubble Sheet
Optical mark recognition (OMR) collects data from people by identifying markings on a paper. OMR enables the hourly processing of hundreds or even thousands of documents. A common application of this technology is used in exams, where students mark cells as their answers. This allows for very fast automated grading of exam sheets. Background Many OMR devices have a scanner that shines a light onto a form. The device then looks at the contrasting reflectivity of the light at certain positions on the form. It will detect the black marks because they reflect less light than the blank areas on the form. Some OMR devices use forms that are printed on transoptic paper. The device can then measure the amount of light that passes through the paper. It will pick up any black marks on either side of the paper because they reduce the amount of light passing through. In contrast to the dedicated OMR device, desktop OMR software allows a user to create their own forms in a word process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paper
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, Textile, rags, poaceae, grasses, Feces#Other uses, herbivore dung, or other vegetable sources in water. Once the water is drained through a fine mesh leaving the fibre evenly distributed on the surface, it can be pressed and dried. The papermaking process developed in east Asia, probably China, at least as early as 105 Common Era, CE, by the Han Dynasty, Han court eunuch Cai Lun, although the earliest archaeological fragments of paper derive from the 2nd century BCE in China. Although paper was originally made in single sheets by hand, today it is mass-produced on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, painting, graphics, signage, design, packaging, decorating, writing, and Housekeeping, cleaning. It may also be used a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Union
The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The union has a total area of and an estimated population of over 449million as of 2024. The EU is often described as a ''sui generis'' political entity combining characteristics of both a federation and a confederation. Containing 5.5% of the world population in 2023, EU member states generated a nominal gross domestic product (GDP) of around €17.935 trillion in 2024, accounting for approximately one sixth of global economic output. Its cornerstone, the European Union Customs Union, Customs Union, paved the way to establishing European Single Market, an internal single market based on standardised European Union law, legal framework and legislation that applies in all member states in those matters, and only those matters, where the states ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Error
Human error is an action that has been done but that was "not intended by the actor; not desired by a set of rules or an external observer; or that led the task or system outside its acceptable limits".Senders, J.W. and Moray, N.P. (1991) Human Error: Cause, Prediction, and Reduction'. Lawrence Erlbaum Associates, p.25. . Human error has been cited as a primary cause and contributing factor in disasters and accidents in industries as diverse as Nuclear and radiation accidents and incidents, nuclear power (e.g., the Three Mile Island accident), Pilot error, aviation, List of spaceflight-related accidents and incidents, space exploration (e.g., the Space Shuttle Challenger disaster and Space Shuttle Columbia disaster), and Medical error, medicine. Prevention of human error is generally seen as a major contributor to Data integrity, reliability and safety of (complex) systems. Human error is one of the many contributing causes of risk events. Definition Human error refers to somethi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opacity (optics)
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc. An opaque object is neither transparent (allowing all light to pass through) nor translucent (allowing some light to pass through). When light strikes an interface between two substances, in general, some may be reflected, some absorbed, some scattered, and the rest transmitted (also see refraction). Reflection can be diffuse, for example light reflecting off a white wall, or specular, for example light reflecting off a mirror. An opaque substance transmits no light, and therefore reflects, scatters, or absorbs all of it. Other categories of visual appearance, related to the perception of regular or diffuse reflection and transmission of light, have been organized under the concept of cesia in an order sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphite
Graphite () is a Crystallinity, crystalline allotrope (form) of the element carbon. It consists of many stacked Layered materials, layers of graphene, typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on a large scale (1.3million metric tons per year in 2022) for uses in many critical industries including refractories (50%), lithium-ion batteries (18%), foundries (10%), and lubricants (5%), among others (17%). Graphite converts to diamond under extremely high pressure and temperature. Graphite's low cost, thermal and chemical inertness and characteristic conductivity of heat and electricity finds numerous applications in high energy and high temperature processes. Types and varieties Graphite can occur naturally or be produced synthetically. Natural graphite is obtained from naturally occurring geologic deposits and synthetic graphite is produced t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmittance
Electromagnetic radiation can be affected in several ways by the medium in which it propagates. It can be Scattering, scattered, Absorption (electromagnetic radiation), absorbed, and Fresnel equations, reflected and refracted at discontinuities in the medium. This page is an overview of the last 3. The transmittance of a material and any surfaces is its effectiveness in transmitting radiant energy; the fraction of the initial (incident) radiation which propagates to a location of interest (often an observation location). This may be described by the transmission coefficient. Surface Transmittance Hemispherical transmittance Hemispherical transmittance of a surface, denoted ''T'', is defined as :T = \frac, where *Φet is the radiant flux ''transmitted'' by that surface into the hemisphere on the opposite side from the incident radiation; *Φei is the radiant flux received by that surface. Hemispheric transmittance may be calculated as an integral over the directional trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visible Spectrum
The visible spectrum is the spectral band, band of the electromagnetic spectrum that is visual perception, visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' (or simply light). The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ultraviolet and infrared parts of the electromagnetic spectrum as well, known collectively as ''optical radiation''. A typical human eye will respond to wavelengths from about 380 to about 750 nanometers. In terms of frequency, this corresponds to a band in the vicinity of 400–790 Terahertz (unit), terahertz. These boundaries are not sharply defined and may vary per individual. Under optimal conditions, these limits of human perception can extend to 310 nm (ultraviolet) and 1100 nm (near infrared). The spectrum does not contain all the colors that the human visual system can distinguish. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phototubes
A phototube or photoelectric cell is a type of gas filled tube, gas-filled or vacuum tube that is sensitive to light. Such a tube is more correctly called a 'photoemissive cell' to distinguish it from photovoltaic or photoconductive cells. Phototubes were previously more widely used but are now replaced in many applications by solid state photodetectors. The photomultiplier tube is one of the most sensitive light detectors, and is still widely used in physics research. Operating principles Phototubes operate according to the photoelectric effect: Incoming photons strike a photocathode, knocking electrons out of its surface, which are attracted to an anode. Thus current is dependent on the frequency and intensity of incoming photons. Unlike photomultiplier tubes, no amplification takes place, so the current through the device is typically of the order of a few microamperes. The light wavelength range over which the device is sensitive depends on the material used for the photo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bar Code
A barcode or bar code is a method of representing data in a visual, Machine-readable data, machine-readable form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, now commonly referred to as linear or one-dimensional (1D), can be scanned by special optical scanners, called barcode readers, of which there are several types. Later, two-dimensional (2D) variants were developed, using rectangles, dots, hexagons and other patterns, called ''2D barcodes'' or ''matrix codes'', although they do not use bars as such. Both can be read using purpose-built 2D optical scanners, which exist in a few different forms. Matrix codes can also be read by a digital camera connected to a microcomputer running software that takes a photographic image of the barcode and analyzes the image to deconstruct and decode the code. A mobile device with a built-in camera, such as a smartphone, can function as the latter type of barcode reader usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scantron Corporation
Scantron Corporation is an American company based in Eagan, Minnesota. Scantron provides assessment solutions and technology services for business, education, certification, and government clients. Scantron Assessment Solutions deals with scanner manufacturing, forms printing, computer-based testing, and the creation of test questions by psychometricians. It operates in 98% of the US school districts, 56 countries, 48 ministries of education, and 94 of the top 100 US universities. The company is well known for their machine-readable paper forms on which students mark answers to multiple-choice test questions and the optical mark recognition (OMR) and imaging scanners that read them. To analyze those answers, the machines use OMR- and image-based data collection software. In addition to its forms and scanners, Scantron provides web- and desktop-based assessment software, such as Performance Series. Scantron Technology Solutions provides managed technology support for IT endpoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Form (document)
A form is a document which contains blank spaces (also named ''fields'' or ''placeholders'') in which one can write or select an option. Forms can be distributed to several signatories at once, or made available on demand. Before being filled out, each copy of a form is usually identical, except, possibly, for a serial number. A form allows an organisation to collect a uniform set of data from many parties in a consistent manner. Forms, when completed, vary in their purpose; for example, a form might be a statement, a request, or an order. A cheque may also be considered a form. In addition, there are several forms for taxes. An example is a tax return; filling one out is required in order for the amount of tax one owes to be determined. A form may also be a request for a tax refund. Forms may be filled out in duplicate (or ''triplicate'', meaning three times) when the information gathered on the form needs to be distributed to several departments within an organisation. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
