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Latency (other)
Latency or latent may refer to: Science and technology * Latent heat, energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process * Latent variable, a variable that is not directly observed but inferred in statistics Biology and medicine * Latency period or latent period, the time between development of a disease or exposure to a pathogen, chemical, or radiation and when symptoms first become apparent (e.g. latent tumor) or when the disease becomes infectious (e.g. infectious disease) * Latent homosexuality, a term proposed by Sigmund Freud * Sleep onset latency, the time it takes a person to fall asleep * Virus latency, the ability of a virus to remain dormant Engineering * Latency (engineering), a measure of the time delay experienced by a system ** Latency (audio), the delay necessitated by the conversion between analog and digital representations of sound data ** CAS latency, computer memory latency ** Network latency or network dela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latent Heat
Latent heat (also known as latent energy or heat of transformation) is energy released or absorbed, by a body or a thermodynamic system, during a constant-temperature process — usually a first-order phase transition. Latent heat can be understood as energy in hidden form which is supplied or extracted to change the state of a substance without changing its temperature. Examples are latent heat of fusion and latent heat of vaporization involved in phase changes, i.e. a substance condensing or vaporizing at a specified temperature and pressure. The term was introduced around 1762 by Scottish chemist Joseph Black. It is derived from the Latin ''latere'' (''to lie hidden''). Black used the term in the context of calorimetry where a heat transfer caused a volume change in a body while its temperature was constant. In contrast to latent heat, sensible heat is energy transferred as heat, with a resultant temperature change in a body. Usage The terms ″sensible heat″ and ″laten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latent Variable
In statistics, latent variables (from Latin: present participle of ''lateo'', “lie hidden”) are variables that can only be inferred indirectly through a mathematical model from other observable variables that can be directly observed or measured. Such ''latent variable models'' are used in many disciplines, including political science, demography, engineering, medicine, ecology, physics, machine learning/artificial intelligence, bioinformatics, chemometrics, natural language processing, management and the social sciences. Latent variables may correspond to aspects of physical reality. These could in principle be measured, but may not be for practical reasons. In this situation, the term ''hidden variables'' is commonly used (reflecting the fact that the variables are meaningful, but not observable). Other latent variables correspond to abstract concepts, like categories, behavioral or mental states, or data structures. The terms ''hypothetical variables'' or ''hypothetical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latency Period
In epidemiology, particularly in the discussion of infectious disease dynamics (modeling), the latent period (also known as the latency period or the pre-infectious period) is the time interval between when an individual or host is infected by a pathogen and when they become infectious, i.e. capable of transmitting pathogens to other susceptible individuals. Relationship with related concepts in infectious disease dynamics To understand the spreading dynamics of an infectious disease or an epidemic, three important time periods should be carefully distinguished: incubation period, pre-infectious or latent period and infectious period. Two other relevant and important time period concepts are generation time and serial interval. The infection of a disease begins when a pathogenic (disease-causing) infectious agent, or a pathogen, is successfully transmitted from one host to another. Pathogens leave the body of one host through a portal of exit, are carried by some mode of trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latent Homosexuality
Latent homosexuality is an erotic attraction toward members of the same sex that is not consciously experienced or expressed in overt action. This may mean a hidden inclination or potential for interest in homosexual relationships, which is either suppressed or not recognized, and which has not yet been explored, or may never be explored. The term was originally proposed by Sigmund Freud. Some argue that latent homosexuality is a potentially iatrogenic effect (that is, it is not present until suggested by a therapist). Others argue that the term latent is not truly applicable in the case of homosexual urges, since they are often not in the unconscious or unexpressed category, but rather exist in the conscious mind and are (often violently) repressed on a conscious level. Links to homophobia A theory that homophobia is a result of latent homosexuality was put forth in the late 20th century. A 1996 study from the University of Georgia by Henry Adams, Lester Wright Jr., and Beth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep Onset Latency
In sleep science, sleep onset latency (SOL) is the length of time that it takes to accomplish the transition from full wakefulness to sleep, normally to the lightest of the non-REM sleep stages. Sleep latency studies Pioneering Stanford University sleep researcher William C. Dement reports early development of the concept, and of the first test for it, the Multiple Sleep Latency Test (MSLT), in his book ''The Promise of Sleep''. Dement and colleagues including Mary Carskadon had been seeking an objective measure of daytime sleepiness to help assess the effects of sleep disorders. In the course of evaluating experimental results, they realized that the amount of time it took to fall asleep in bed was closely linked to the subjects' own self-evaluated level of sleepiness. "This may not seem like an earthshaking epiphany, but conceiving and developing an objective measure of sleepiness was perhaps one of the most important advances in sleep science," Dement and coauthor Christopher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus Latency
Virus latency (or viral latency) is the ability of a pathogenic virus to lie dormant (latent) within a cell, denoted as the lysogenic part of the viral life cycle. A latent viral infection is a type of persistent viral infection which is distinguished from a chronic viral infection. Latency is the phase in certain viruses' life cycles in which, after initial infection, proliferation of virus particles ceases. However, the viral genome is not eradicated. The virus can reactivate and begin producing large amounts of viral progeny (the lytic part of the viral life cycle) without the host becoming reinfected by new outside virus, and stays within the host indefinitely. Virus latency is not to be confused with clinical latency during the incubation period when a virus is ''not'' dormant. Mechanisms Episomal latency Episomal latency refers to the use of genetic episomes during latency. In this latency type, viral genes are stabilized, floating in the cytoplasm or nucleus as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latency (engineering)
Latency, from a general point of view, is a time delay between the cause and the effect of some physical change in the system being observed. Lag, as it is known in gaming circles, refers to the latency between the input to a simulation and the visual or auditory response, often occurring because of network delay in online games. Latency is physically a consequence of the limited velocity at which any physical interaction can propagate. The magnitude of this velocity is always less than or equal to the speed of light. Therefore, every physical system with any physical separation (distance) between cause and effect will experience some sort of latency, regardless of the nature of the stimulation at which it has been exposed to. The precise definition of latency depends on the system being observed or the nature of the simulation. In communications, the lower limit of latency is determined by the medium being used to transfer information. In reliable two-way communication syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latency (audio)
Latency refers to a short period of delay (usually measured in milliseconds) between when an audio signal enters a system and when it emerges. Potential contributors to latency in an audio system include analog-to-digital conversion, buffering, digital signal processing, transmission time, digital-to-analog conversion and the speed of sound in the transmission medium. Latency can be a critical performance metric in professional audio including sound reinforcement systems, foldback systems (especially those using in-ear monitors) live radio and television. Excessive audio latency has the potential to degrade call quality in telecommunications applications. Low latency audio in computers is important for interactivity. Telephone calls In all systems, latency can be said to consist of three elements: codec delay, playout delay and network delay. Latency in telephone calls is sometimes referred to as delay; the telecommunications industry also uses the term ''quality of experie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CAS Latency
Column Address Strobe (CAS) latency, or CL, is the delay in clock cycles between the READ command and the moment data is available. In asynchronous DRAM, the interval is specified in nanoseconds (absolute time). In synchronous DRAM, the interval is specified in clock cycles. Because the latency is dependent upon a number of clock ticks instead of absolute time, the actual time for an SDRAM module to respond to a CAS event might vary between uses of the same module if the clock rate differs. RAM operation background Dynamic RAM is arranged in a rectangular array. Each row is selected by a horizontal ''word line''. Sending a logical high signal along a given row enables the MOSFETs present in that row, connecting each storage capacitor to its corresponding vertical ''bit line''. Each bit line is connected to a ''sense amplifier'' that amplifies the small voltage change produced by the storage capacitor. This amplified signal is then output from the DRAM chip as well as driven ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Latency
Network delay is a design and performance characteristic of a telecommunications network. It specifies the latency for a bit of data to travel across the network from one communication endpoint to another. It is typically measured in multiples or fractions of a second. Delay may differ slightly, depending on the location of the specific pair of communicating endpoints. Engineers usually report both the maximum and average delay, and they divide the delay into several parts: * Processing delay time it takes a router to process the packet header * Queuing delay time the packet spends in routing queues * Transmission delay time it takes to push the packet's bits onto the link * Propagation delay time for a signal to propagate through the media A certain minimum level of delay is experienced by signals due to the time it takes to transmit a packet serially through a link. This delay is extended by more variable levels of delay due to network congestion. IP network delays can range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotational Latency
Higher performance in hard disk drives comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories: access time and data transfer time (or rate). Access time The ''access time'' or ''response time'' of a rotating drive is a measure of the time it takes before the drive can actually transfer data. The factors that control this time on a rotating drive are mostly related to the mechanical nature of the rotating disks and moving heads. It is composed of a few independently measurable elements that are added together to get a single value when evaluating the performance of a storage device. The access time can vary significantly, so it is typically provided by manufacturers or measured in benchmarks as an average. The key components that are typically added together to obtain the access time are: * Seek time * Rotational latency * Command processing time * Settle time Seek time With rotating drives, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latency Stage
The latency stage is the fourth stage of Sigmund Freud's model of a child's psychosexual development. Freud believed that the child discharges their libido (sexual energy) through a distinct body area that characterizes each stage. The stages are: *the 'oral phase' (first stage) *the 'anal phase' (second stage) *the 'phallic phase' (third stage) *the 'latency phase' (fourth stage) *the 'genital phase' (fifth stage). In general The latency stage may begin around the age of 7 (the end of early childhood) and may continue until puberty, which happens around the age of 13. The age range is affected by childrearing practices; mothers in developed countries, during the time when Freud was forming his theories, were more likely to stay at home with young children, and adolescents began puberty on average later than adolescents today. Freud described the latency phase as one of relative stability. No new organization of sexuality develops, and he did not pay a lot of attention to it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
