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Decoupling
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The term "decoupling" is used in many different contexts.
a class="link1" onMouseover='showByLink("m3123113",this)' onMouseout='hide("m3123113")'href="http://www.absoluteastronomy.com/topics/Physics">physics, decoupling is the general phenomenon in which the interactions between some physical objects (such as elementary particles) disappear.
In gauge theories, there are unobserved polarizations of elementary particles, such as the longitudinal photon. The experiments as well as theoretical consistency dictates that these polarizations cannot be produced by collisions of other particles.
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Encyclopedia
The term "decoupling" is used in many different contexts.
Physics
In physics, decoupling is the general phenomenon in which the interactions between some physical objects (such as elementary particles) disappear.
In gauge theories, there are unobserved polarizations of elementary particles, such as the longitudinal photon. The experiments as well as theoretical consistency dictates that these polarizations cannot be produced by collisions of other particles. Consequently, their interactions with other (physical) particles must be equal to zero, and quantum electrodynamics confirms this expectation: decoupling is a consequence of gauge symmetry.
Physical cosmology
In physical cosmology, the term "decoupling" is often used for the moment during recombination when the rate of Compton scattering became slower than the expansion of the universe, producing Cosmic Microwave Background as we know it.
Software Development
In Software Development, the term "decoupling" is used to identify the separation of software blocks that shouldn't depend on each other. Some building blocks are generic and shouldn't know details of others. Special design techniques allow software designers to have as little dependencies as possible. This typically reduces the risk of malfunction in one part of a system when the other part changed. It also forces the developer to focus on one thing at a time.
Biology
In biology, decoupling (used interchangeably with uncoupling) refers to the separation of the energy stored in the ion gradients inside mitochondria from the synthesis of ATP. Since this energy is not used to do work, it is dissipated as heat. This strategy is used by hibernating animals and infants to keep warm because their heat energy needs are higher than their ATP needs. Artificial decoupling has been used as a diet aid, often with disastrous results.
Neuropsychopharmacology
In neuropsychopharmacology, uncoupling (or decoupling) is a term often used to describe when receptor or ligand binding sites/domains become separated or move alignments or become internalised as a result of physiological tolerance to exposure over a period of time to a pharmacologically active psychoactive substance or toxin.
Electronics
In electronics, decoupling refers to the preventing of undesired coupling between subsystems via the power supply connections. Nowadays, this is commonly accomplished by connecting localized capacitors close to the power leads of integrated circuits to act as a small localized energy reservoir; these supply the circuit with current during transient, high current demand periods, preventing the voltage on the power supply rail from being pulled down by the momentary current load. See decoupling capacitor.
Rail transport
In rail transport, decoupling is the separation of two railroad cars by manipulation of their couplers.
Inventory management
In Inventory Management, decoupling allows economy of scale within a single facility, and permits each process to operate at maximum efficiency rather than having the speed of the entire process constrained by the slowest.
Nuclear testing
In the underground nuclear testing (the testing of nuclear weapons), decoupling refers to the attempt to prevent some of the bomb's energy from transmitting as seismic waves. This makes it more difficult for outside observers to estimate the nuclear yield of the weapon being tested.
Mathematics
In mathematics, decoupling refers to the rearrangement of systems of equations so that they are independent of each other.
Utility Regulation
In public utility regulation, decoupling refers to the disassociation of a utility's profits from its sales of the energy commodity. Instead, a rate of return is aligned with meeting revenue targets, and rates are trued up or down to meet the target at the end of the adjustment period. This makes the utility indifferent to selling less product and improves the ability of energy efficiency and distributed generation to operate within the utility environment.
Ideally, utilities should be rewarded based on how well they meet their customers' energy service needs. However, most current rate designs place the focus on commodity sales instead, tying a distribution company's recovery of fixed costs directly to its commodity sales.
In order to motivate utilities to consider all the options when planning and making resource decisions on how to meet their customers' needs, the sales-revenue link in current rate design must be broken. Breaking that link between the utility's commodity sales and revenues, removes both the incentive to increase electricity sales and the disincentive to run effective energy efficiency programs or invest in other activities that may reduce load. Decision-making then refocuses on making least-cost investments to deliver reliable energy services to customers even when such investments reduce throughput. The result is a better alignment of shareholder and customer interests to provide for more economically and environmentally efficient resource decisions.
As an added benefit, breaking the sales-revenue link streamlines the regulatory process for rate adjustments. Contention over sales forecasts consumes extensive time in every rate case. If the sales-revenue link is broken, these forecasts carry no economic weight, so the incentive to game forecasts of electricity sales is removed and rate cases become less adversarial.
Economics
In economics, decoupling is often used in the context of economic production and environmental quality. In this context, it refers to the ability of an economy to grow without corresponding increases in environmental pressure. In many economies increasing production (GDP) would involve increased pressure on the environment. An economy that is able to sustain GDP growth, without also experiencing a worsening of environmental conditions, is said to be decoupled. Exactly how, if, or to what extent this can be achieved is a subject of much debate.
Similarly, decoupling can refer to "breaking" the link between a dependent variable and its cause for a specific industry or activity. For instance, decoupling green house gas emissions from increasing electrical power generation.
The OECD has made decoupling a major focus of the work of its Environment Directorate. The OECD defines the term as follows:
- The term 'decoupling' refers to breaking the link between “environmental bads”and “economic goods.”
The same document then, in the following sentence, redefines the term in implementation language as meaning to have the rates of increasing wealth greater than the rates of increasing impacts. That alteration skirts the clear meaning of the term and the entire dilemma of continually accelerating our remaking of the earth from its effects. (OECD, 2002)
Decoupling and the stock market declines of January 2008
Decoupling holds that European and Asian economies, especially emerging ones, have broadened and deepened to the point that they no longer depend on the United States for growth, leaving them insulated from a severe slowdown there, even a fully fledged recession. Faith in the concept has generated strong outperformance for stocks outside the United States.
In January 2008 as fears of recession mounted in the United States, stocks declined heavily. Contrary to what the decouplers would have expected, the losses were greater outside the United States, with the worst experienced in emerging markets and developed economies like Germany and Japan. Exports make up especially large portions of economic activity in those places, but that was not supposed to matter anymore in a decoupled world because domestic activity was thought to be so robust.
Advertising
Decoupling in advertising is the process whereby advertisers buy services direct from suppliers which were previously sub-contractors to their advertising agencies. Decoupling is discussed in "Magic and Logic" www.magicandlogic.co.uk, the booklet prepared for the Value Framework Steering Group which is a joint venture by the UK trade bodies CIPS, IPA and ISBA. Decoupling is part of the unbundling of the services previously provided by traditional full service advertising agencies, which originally began with the creation of standalone media buying agencies such as Zenith from Saatchi & Saatchi Group in the '80's and Mindshare from WPP group in the '90's. For the same reasons as media (focus, economies of scale and dedicated software) press production is now increasingly handled by standalone Production Agencies, which trade direct with advertisers and not through their advertising agencies.
See also
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