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Relaxation Theorem
Relaxation stands quite generally for a release of tension, a return to equilibrium. In the sciences, the term is used in the following ways: * Relaxation (physics), and more in particular: ** Relaxation (NMR), processes by which nuclear magnetization returns to the equilibrium distribution ** Dielectric relaxation, the delay in the dielectric constant of a material ** Vibrational energy relaxation, the process by which molecules in high energy quantum states return to the Maxwell-Boltzmann distribution ** Chemical relaxation methods, related to temperature jump ** Relaxation oscillator, a type of electronic oscillator In mathematics: :* Relaxation (approximation), a technique for transforming hard constraints into easier ones :* Relaxation (iterative method), a technique for the numerical solution of equations :* Relaxation (extension method), a technique for a natural extension in mathematical optimization or variational problems In computer science: :* Relaxation (computing), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relaxation (physics)
In the physical sciences, relaxation usually means the return of a perturbed system into equilibrium. Each relaxation process can be categorized by a relaxation time τ. The simplest theoretical description of relaxation as function of time ''t'' is an exponential law (exponential decay A quantity is subject to exponential decay if it decreases at a rate proportional to its current value. Symbolically, this process can be expressed by the following differential equation, where is the quantity and (lambda) is a positive rate ...). In simple linear systems Mechanics: Damped unforced oscillator Let the homogeneous differential equation: :m\frac+\gamma\frac+ky=0 model damped harmonic oscillator, damped unforced oscillations of a weight on a spring. The displacement will then be of the form y(t) = A e^ \cos(\mu t - \delta). The constant T (=2m/\gamma) is called the relaxation time of the system and the constant μ is the quasi-frequency. Electronics: RC circuit In an RC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathological state'' refers to abnormal conditions, including human diseases. The Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Foundations Cells Although there are differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tension (music)
In music, tension is the anticipation music creates in a listener's mind for relaxation or release. For example, tension may be produced through reiteration, increase in dynamic level, gradual motion to a higher or lower pitch, or (partial) syncopations between consonance and dissonance. Experiments in music perception have explored perceived tension in music and perceived emotional intensity. The balance between tension and repose are explored in musical analysis—determined by contrasts that are, "...of great interest to the style analyst," and can be analyzed in several, even conflicting layers—as different musical elements such as harmony may create different levels of tension than rhythm and melody.White, John D. (1976). ''The Analysis of Music'', p.15. . See also * Conclusion (music) * Musical argument * Variation (music) In music, variation is a formal technique where material is repeated in an altered form. The changes may involve melody, rhythm, harmony, co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leisure
Leisure has often been defined as a quality of experience or as free time. Free time is time spent away from business, work, job hunting, domestic chores, and education, as well as necessary activities such as eating and sleeping. Leisure as an experience usually emphasizes dimensions of perceived freedom and choice. It is done for "its own sake", for the quality of experience and involvement. Other classic definitions include Thorsten Veblen's (1899) of "nonproductive consumption of time." Free time is not easy to define due to the multiplicity of approaches used to determine its essence. Different disciplines have definitions reflecting their common issues: for example, sociology on social forces and contexts and psychology as mental and emotional states and conditions. From a research perspective, these approaches have an advantage of being quantifiable and comparable over time and place. Leisure studies and sociology of leisure are the academic disciplines concerned w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relaxado En Persona
' (modern spelling: ) was a Spanish legal phrase, literally meaning "relaxed in person", meaning "transferred to the secular authorities", an euphemism for "burnt at the stake Death by burning (also known as immolation) is an execution and murder method involving combustion or exposure to extreme heat. It has a long history as a form of public capital punishment, and many societies have employed it as a punishment ..." in the records of the Spanish Inquisition, since the church tribunal could not execute death sentences. The majority of those "relaxed in person" from 1484 onwards were (relapsed Jews) or (heretics, but also often Jews). Use of the term in source material continues until 1659 or later. Examples: * . * '. * The noun form is (literally "relaxation in person"), but the noun form is primarily used by historians rather than contemporaries. Historians may also use the term anachronistically, for example as in the case of the last burning in Peru, that of Mari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relaxation Technique
A relaxation technique (also known as relaxation training) is any method, process, procedure, or activity that helps a person to relax; to attain a state of increased calmness; or otherwise reduce levels of pain, anxiety, stress or anger. Relaxation techniques are often employed as one element of a wider stress management program and can decrease muscle tension, lower the blood pressure and slow heart and breath rates, among other health benefits. People respond to stress in different ways, namely, by becoming overwhelmed, depressed or both. Yoga, QiGong, Taiji, and Pranayama that includes deep breathing tend to calm people who are overwhelmed by stress, while rhythmic exercise improves the mental and physical health of those who are depressed. People who encounter both symptoms simultaneously, feeling depressed in some ways and overexcited in others, may do best by walking or performing yoga techniques that are focused on strength. Background Research has indicated that remo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relaxation (psychology)
Relaxation in psychology is the emotional state of a living being, of low tension, in which there is an absence of arousal, particularly from negative sources such as anger, anxiety, or fear. According to Oxford Dictionaries relaxation is when the body and mind are free from tension and anxiety. Relaxation is a form of mild ecstasy coming from the frontal lobe of the brain in which the backward cortex sends signals to the frontal cortex via a mild sedative. Relaxation can be achieved through meditation Meditation is a practice in which an individual uses a technique – such as mindfulness, or focusing the mind on a particular object, thought, or activity – to train attention and awareness, and achieve a mentally clear and emotionally calm ..., autogenics, and progressive muscle relaxation. Relaxation helps improve coping with stress (psychological), stress. Stress is the leading cause of mental problems and physical problems, therefore feeling relaxed is beneficial for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recreation
Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasure and are considered to be "fun". Etymology The term ''recreation'' appears to have been used in English first in the late 14th century, first in the sense of "refreshment or curing of a sick person", and derived turn from Latin (''re'': "again", ''creare'': "to create, bring forth, beget"). Prerequisites to leisure People spend their time on activities of daily living, work, sleep, social duties and leisure, the latter time being free from prior commitments to physiologic or social needs, a prerequisite of recreation. Leisure has increased with increased longevity and, for many, with decreased hours spent for physical and economic survival, yet others argue that time pressure has increased for modern people, as they are committed to too ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meditation
Meditation is a practice in which an individual uses a technique – such as mindfulness, or focusing the mind on a particular object, thought, or activity – to train attention and awareness, and achieve a mentally clear and emotionally calm and stable state. Meditation is practiced in numerous religious traditions. The earliest records of meditation (''dhyana'') are found in the Upanishads, and meditation plays a salient role in the contemplative repertoire of Jainism, Buddhism and Hinduism. Since the 19th century, Asian meditative techniques have spread to other cultures where they have also found application in non-spiritual contexts, such as business and health. Meditation may significantly reduce stress, anxiety, depression, and pain, and enhance peace, perception, self-concept, and well-being. Research is ongoing to better understand the effects of meditation on health (psychology, psychological, neurology, neurological, and cardiovascular) and other areas. Etymol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypnosis
Hypnosis is a human condition involving focused attention (the selective attention/selective inattention hypothesis, SASI), reduced peripheral awareness, and an enhanced capacity to respond to suggestion.In 2015, the American Psychological Association Division 30 defined hypnosis as a "state of consciousness involving focused attention and reduced peripheral awareness characterized by an enhanced capacity for response to suggestion". For critical commentary on this definition, see: There are competing theories explaining hypnosis and related phenomena. ''Altered state'' theories see hypnosis as an altered state of mind or trance, marked by a level of awareness different from the ordinary Consciousness, state of consciousness. In contrast, ''non-state'' theories see hypnosis as, variously, a type of placebo effect,Kirsch, I., "Clinical Hypnosis as a Nondeceptive Placebo", pp. 211–25 in Kirsch, I., Capafons, A., Cardeña-Buelna, E., Amigó, S. (eds.), ''Clinical Hypnosis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relaxation (computing)
In computing, a linker or link editor is a computer system program that takes one or more object files (generated by a compiler or an assembler) and combines them into a single executable file, library file, or another "object" file. A simpler version that writes its output directly to memory is called the ''loader'', though loading is typically considered a separate process. Overview Computer programs typically are composed of several parts or modules; these parts/modules do not need to be contained within a single object file, and in such cases refer to each other by means of symbols as addresses into other modules, which are mapped into memory addresses when linked for execution. While the process of linking is meant to ultimately combine these independent parts, there are many good reasons to develop those separately at the source-level. Among these reasons are the ease of organizing several smaller pieces over a monolithic whole and the ability to better define the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relaxation (NMR)
In MRI and NMR spectroscopy, an observable nuclear spin polarization ( magnetization) is created by a homogeneous magnetic field. This field makes the magnetic dipole moments of the sample precess at the resonance ( Larmor) frequency of the nuclei. At thermal equilibrium, nuclear spins precess randomly about the direction of the applied field. They become abruptly phase coherent when they are hit by radiofrequent (RF) pulses at the resonant frequency, created orthogonal to the field. The RF pulses cause the population of spin-states to be perturbed from their thermal equilibrium value. The generated transverse magnetization can then induce a signal in an RF coil that can be detected and amplified by an RF receiver. The return of the longitudinal component of the magnetization to its equilibrium value is termed ''spin-lattice'' relaxation while the loss of phase-coherence of the spins is termed ''spin-spin'' relaxation, which is manifest as an observed free induction decay (FID). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
