The user interface, in the industrial design field of human–computer interaction, is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine from the human end, whilst the machine feeds back information that aids the operators' decision-making process. Examples of this broad concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls, process controls; the design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology. The goal of user interface design is to produce a user interface which makes it easy and enjoyable to operate a machine in the way which produces the desired result; this means that the operator needs to provide minimal input to achieve the desired output, that the machine minimizes undesired outputs to the human. User interfaces are composed of one or more layers including a human-machine interface interfaces machines with physical input hardware such a keyboards, game pads and output hardware such as computer monitors and printers.
A device that implements a HMI is called a human interface device. Other terms for human-machine interfaces are man–machine interface and when the machine in question is a computer human–computer interface. Additional UI layers may interact with one or more human sense, including: tactile UI, visual UI, auditory UI, olfactory UI, equilibrial UI, gustatory UI. Composite user interfaces are UIs that interact with two or more senses; the most common CUI is a graphical user interface, composed of a tactile UI and a visual UI capable of displaying graphics. When sound is added to a GUI it becomes a multimedia user interface. There are three broad categories of CUI: standard and augmented. Standard composite user interfaces use standard human interface devices like keyboards and computer monitors; when the CUI blocks out the real world to create a virtual reality, the CUI is virtual and uses a virtual reality interface. When the CUI does not block out the real world and creates augmented reality, the CUI is augmented and uses an augmented reality interface.
When a UI interacts with all human senses, it is called a qualia interface, named after the theory of qualia. CUI may be classified by how many senses they interact with as either an X-sense virtual reality interface or X-sense augmented reality interface, where X is the number of senses interfaced with. For example, a Smell-O-Vision is a 3-sense Standard CUI with visual display and smells; the user interface or human–machine interface is the part of the machine that handles the human–machine interaction. Membrane switches, rubber keypads and touchscreens are examples of the physical part of the Human Machine Interface which we can see and touch. In complex systems, the human–machine interface is computerized; the term human–computer interface refers to this kind of system. In the context of computing, the term extends as well to the software dedicated to control the physical elements used for human-computer interaction; the engineering of the human–machine interfaces is enhanced by considering ergonomics.
The corresponding disciplines are human factors engineering and usability engineering, part of systems engineering. Tools used for incorporating human factors in the interface design are developed based on knowledge of computer science, such as computer graphics, operating systems, programming languages. Nowadays, we use the expression graphical user interface for human–machine interface on computers, as nearly all of them are now using graphics. There is a difference between a user interface and an operator interface or a human–machine interface; the term "user interface" is used in the context of computer systems and electronic devices Where a network of equipment or computers are interlinked through an MES -or Host to display information. A human-machine interface is local to one machine or piece of equipment, is the interface method between the human and the equipment/machine. An operator interface is the interface method by which multiple equipment that are linked by a host control system is accessed or controlled.
The system may expose several user interfaces to serve different kinds of users. For example, a computerized library database might provide two user interfaces, one for library patrons and the other for library personnel; the user interface of a mechanical system, a vehicle or an industrial installation is sometimes referred to as the human–machine interface. HMI is a modification of the original term MMI. In practice, the abbreviation MMI is still used although some may claim that MMI stands for something different now. Another abbreviation is HCI, but is more used for human–computer interaction. Other terms used are operator interface terminal; however it is abbreviated, the terms refer to the'layer' that separates a human, operating a machine from the machine itself. Without a clean and usable interface, humans would not be able to
Gene redundancy is the existence of multiple genes in the genome of an organism that perform the same function. This is the case for many sets of paralogous genes; when an individual gene in such a set is disrupted by mutation or targeted knockout, there can be little effect on phenotype as a result of gene redundancy, whereas the effect is large for the knockout of a gene with only one copy. Gene redundancy most results from Gene duplication; when a gene is duplicated within a genome, the two copies are functionally redundant. Three of the more common mechanisms of gene duplication are retroposition, unequal crossing over, non-homologous segmental duplication. Retroposition is when the mRNA transcript of a gene is reverse transcribed back into DNA and inserted into the genome at a different location. During unequal crossing over, homologous chromosomes exchange uneven portions of their DNA; this can lead to the transfer of one chromosome's gene to the other chromosome, leaving two of the same gene on one chromosome, no copies of the gene on the other chromosome.
Non-homologous duplications result from replication errors that shift the gene of interest into a new position. A tandem duplication occurs, creating a chromosome with two copies of the same gene. Figure 1 to the left provides a good visual explanation of these three mechanisms; as the genome is replicated over many generations, the redundant gene's function will most evolve due to Genetic drift. This means; the three mechanisms of functional differentiation in genes are nonfunctionalization, neofunctionalization and subfunctionalization. During nonfunctionalization, or degeneration/gene loss, one copy of the duplicated gene acquires mutations that render it inactive or silent. At this time, the gene is called a pseudogene. Pseudogenes can be lost over time due to genetic mutations. Neofunctionalization occurs when one copy of the gene accumulates mutations that give the gene a new, beneficial function, different than the original function. Subfunctionalization occurs; each copy becomes only active.
Figure 2 to the right provides a visual explanation. The evolution and origin of redundant genes remain unknown because evolution happens over such a long period of time. Theoretically, a gene can not be maintained without mutation unless it has a selective pressure acting on it. Gene redundancy, would allow both copies of the gene to accumulate mutations as long as the other was still able to perform its function; this means that all redundant genes should theoretically become a pseudogene and be lost. Scientists have devised two hypothesis as to why redundant genes can remain in the genome: the backup hypothesis and the piggyback hypothesis; the backup hypothesis proposes that redundant genes remain in the genome as a sort of "back-up plan". If the original gene loses its function, the redundant gene is there to take over and keep the cell alive; the piggyback hypothesis states that two paralogs in the genome have some kind of non-overlapping function as well as the redundant function. In this case, the redundant part of the gene remains in the genome due to the proximity to the area that codes for the unique function.
The reason redundant genes remain in the genome is an ongoing question and gene redundancy is being studied by researchers everywhere. There are many hypotheses in addition to the piggyback models. For example, at the University of Michigan, a study provides the theory that redundant genes are maintained in the genome by reduced expression. Researchers use the history of redundant genes in the form of gene families to learn about the phylogeny of a species, it takes time for redundant genes to undergo functional diversification. Gene duplication events can be detected by looking at increases in gene duplicates. A good example of using gene redundancy in evolutionary studies is the Evolution of the KCS gene family in plants; this paper studies. The number of redundant genes in the species allows researchers to determine when duplication events took place and how related species are. There are three ways to detect paralogs in a known genomic sequence: simple homology, gene family evolution and orthology.
Since the Human Genome Project's completion, researchers are able to annotate the human genome much more easily. Using online databases like the Genome Browser at UCSC, researchers can look for homology in the sequence of their gene of interest; the Human Olfactory Receptor gene family contains 297 pseudogenes. These genes are found in different locations throughout the genome, but only about 13% are on different chromosomes or on distantly spaced loci. 172 subfamilies of OR genes have been found in each at its own loci. Because the genes in each of these subfamilies are structurally and functionally similar, in close proximity to each other, it is hypothesized that each evolved from single genes undergoing duplication events; the high number of subfamilies in humans explains. Human OR genes have homologues in other mammals, such as mice, that demonstrate the evolution of Olfactory Receptor genes. One particular family, involved in the initial event of odor perception has been found to be conserved throughout all of vertebrate evolution.
Duplication events and redundant
"Redundant" is a song by American punk rock band Green Day. It was released as the third single from Nimrod; the song failed to match the chart positions of its predecessors but did reach number two in Australia when it was reissued as a double A-side with "Good Riddance", becoming the band's highest-charting single there. It is one of few Green Day songs in which vocalist/guitarist Billie Joe Armstrong uses an effects pedal. Before the Nimrod sessions, Billie Joe Armstrong's marriage had been deteriorating, with the singer arguing with his wife Adrienne Armstrong constantly. Influenced by this conflict, Armstrong reflected on the relationship from two standpoints; the phrase "I love you" had lost its effectiveness and seemed to be said out of routine. The music video for "Redundant", directed by Mark Kohr, is an homage to Zbigniew Rybczyński's short film Tango, it features the three band members performing the song in the middle of a home. The camera angle remains static for the duration of the video.
In the background, several people repeat various mundane tasks for the duration of the video: A newspaper is thrown from offscreen. A woman stretches her arms and yawns, collects the paper and leaves. Someone replaces it with a new one. An old lady tries to find her way out. A young girl walks from the left side of the screen, places a box on the coffee table next to the couch, climbs out of a window. A man in a green suit jacket picks up the box from the coffee table and leaves. A man in a cowboy hat walks around. A woman in a bright red dress removes her dress and walks away in nothing but her bra and shorts. A balding man comes in, puts on a pair of trousers leaves. An obese man walks in from putting it on a table by the wall. A woman with a large pot walks around. A man and a girl begin making out. A man is vacuuming. A young girl in a skirt comes in through a window, looks around, leaves; the activity peaks near the middle of the video and declines near the end. Tré and Mike leave, but Billie Joe removes his guitar, hands it offscreen, picks up the newspaper before walking away.
The woman screams upon finding it gone. 7-inch Vinyl box set
In engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system in the form of a backup or fail-safe, or to improve actual system performance, such as in the case of GNSS receivers, or multi-threaded computer processing. In many safety-critical systems, such as fly-by-wire and hydraulic systems in aircraft, some parts of the control system may be triplicated, formally termed triple modular redundancy. An error in one component may be out-voted by the other two. In a triply redundant system, the system has three sub components, all three of which must fail before the system fails. Since each one fails, the sub components are expected to fail independently, the probability of all three failing is calculated to be extraordinarily small. Redundancy may be known by the terms "majority voting systems" or "voting logic". Redundancy sometimes produces less, instead of greater reliability – it creates a more complex system, prone to various issues, it may lead to human neglect of duty, may lead to higher production demands which by overstressing the system may make it less safe.
In computer science, there are four major forms of redundancy, these are: Hardware redundancy, such as dual modular redundancy and triple modular redundancy Information redundancy, such as error detection and correction methods Time redundancy, performing the same operation multiple times such as multiple executions of a program or multiple copies of data transmitted Software redundancy such as N-version programmingA modified form of software redundancy, applied to hardware may be: Distinct functional redundancy, such as both mechanical and hydraulic braking in a car. Applied in the case of software, code written independently and distinctly different but producing the same results for the same inputs. Structures are designed with redundant parts as well, ensuring that if one part fails, the entire structure will not collapse. A structure without redundancy is called fracture-critical, meaning that a single broken component can cause the collapse of the entire structure. Bridges that failed due to lack of redundancy include the Silver Bridge and the Interstate 5 bridge over the Skagit River.
Parallel and combined systems demonstrate different level of redundancy. The models are subject of studies in safety engineering; the two functions of redundancy are passive active redundancy. Both functions prevent performance decline from exceeding specification limits without human intervention using extra capacity. Passive redundancy uses excess capacity to reduce the impact of component failures. One common form of passive redundancy is the extra strength of cabling and struts used in bridges; this extra strength allows some structural components to fail without bridge collapse. The extra strength used in the design is called the margin of safety. Eyes and ears provide working examples of passive redundancy. Vision loss in one eye does not cause blindness but depth perception is impaired. Hearing loss in one ear does not cause deafness but directionality is impaired. Performance decline is associated with passive redundancy when a limited number of failures occur. Active redundancy eliminates performance declines by monitoring the performance of individual devices, this monitoring is used in voting logic.
The voting logic is linked to switching. Error detection and correction and the Global Positioning System are two examples of active redundancy. Electrical power distribution provides an example of active redundancy. Several power lines connect each generation facility with customers; each power line includes monitors. Each power line includes circuit breakers; the combination of power lines provides excess capacity. Circuit breakers disconnect a power line. Power is redistributed across the remaining lines. Charles Perrow, author of Normal Accidents, has said that sometimes redundancies backfire and produce less, not more reliability; this may happen in three ways: First, redundant safety devices result in a more complex system, more prone to errors and accidents. Second, redundancy may lead to shirking of responsibility among workers. Third, redundancy may lead to increased production pressures, resulting in a system that operates at higher speeds, but less safely. Voting logic uses performance monitoring to determine how to reconfigure individual components so that operation continues without violating specification limitations of the overall system.
Voting logic involves computers, but systems composed of items other than computers may be reconfigured using voting logic. Circuit breakers are an example of a form of non-computer voting logic. Electrical power systems use power scheduling to reconfigure active redundancy. Computing systems adjust the production output of each generating facility when other generating facilities are lost; this prevents blackout conditions during major events such as an earthquake. The simplest voting logic in computing systems involves two components: alternate, they both run similar software, but the output from the alternate remains inactive during normal operation. The primary monitors itself and periodically sends an activity message to the alternate as long as everything is OK. All outputs from the primary stop, including the activity message; the alternate activates its output and takes over from the primary after a brief delay when the activity message ceases. Errors in voting logic can cause both outputs to be active or inactive at the same time, or cause output