Crossword clues for drawdown
Douglas Harper's Etymology Dictionary
Wiktionary
n. 1 The act of reduction or depletion. 2 The result of reduction or depletion. 3 A change in http://en.wikipedia.org/wiki/hydraulic%20head in a well or other body of water. 4 (context economics English) A measure of the decline from a historical peak in some variable, typically the cumulative profit or total open equity of a financial trading strategy.
Wikipedia
Drawdown may refer to:
- Drawdown (economics), decline in the value of an investment, below its all-time high
- Drawdown (hydrology), a lowering of a reservoir or a change in hydraulic head in an aquifer, typically due to pumping a well
- Drawdown card, used for testing paints and coatings through wet film preparation
- Drawdown chart, paper used to test various coating properties
- Income Drawdown, a method withdrawing benefits from a UK Registered Pension Scheme
In water-related science and engineering there are two similar but distinct definitions in use for drawdown.
- In subsurface hydrogeology, drawdown is the change in hydraulic head observed at a well in an aquifer, typically due to pumping a well as part of an aquifer test or well test.
- In surface water hydrology and civil engineering, drawdown refers to the lowering of the water level in a man-made reservoir or tank.
In either case, drawdown is the change in head or water level relative to background condition, indicating the difference in head which has occurred at a given location relative to an initial time at the same location.
A record of hydraulic head through time is more generally called a hydrograph (in both groundwater and surface water).
The drawdown is the measure of the decline from a historical peak in some variable (typically the cumulative profit or total open equity of a financial trading strategy).
Somewhat more formally, if X = (X(t), t ≥ 0) is a random process with X(0) = 0, the drawdown at time T, denoted D(T), is defined as
D(T) = max{0, maxX(t) − X(T)}
The maximum drawdown (MDD) up to time T is the maximum of the Drawdown over the history of the variable. More formally,
MDD(T) = max[maxX(t) − X(τ)]
The following pseudocode computes the Drawdown ("DD") and Max Drawdown ("MDD") of the variable "NAV", the Net Asset Value of an investment. Drawdown and Max Drawdown are calculated as percentages:
MDD = 0
peak = -99999
for i = 1 to N step 1
# peak will be the maximum value seen so far (0 to i), only get updated when higher NAV is seen
if (NAV[i] > peak)
peak = NAV[i]
endif
DD[i] = 100.0 * (peak - NAV[i]) / peak
# Same idea as peak variable, MDD keeps track of the maximum drawdown so far. Only get updated when higher DD is seen.
if (DD[i] > MDD)
MDD = DD[i]
endif
endfor
Climate drawdown is the point at which greenhouse gas concentrations in the atmosphere begin to decline on a year-to-year basis.
Drawdown is a goal for reversing climate change, and eventually reducing global average temperatures.
Usage examples of "drawdown".
The drawdown was not a permanent reprieve, merely an incident in a bureaucratic summer.
Perhaps when the drawdown was complete, they could locate the time capsule which now seemed so valuable.
Duke consulted his notes on the technical aspects of the drawdown, and called the conference to order.
Before the drawdown the stream had been swallowed by the expanse of Breedlove Lake, existing only as a current within the reservoir, but now it had been freed to course through its own eroded canyon, through seasons of silt, as it cut its way to the muddy waters of the great Watauga, pulsing again through the heart of the valley.
The admiral had played a key part in the logistics buildup that helped force Iraq out of Kuwait and had later counseled that the drawdown of forces from Saudi Arabia following the successful conclusion of the war, leaving only a small trip-wire force in Kuwait and massive military stockpiles in the Saudi desert, was premature.
A finger run along the serrated edges and a tiny drawdown of power, and the two layers sealed themselves together again.
Great Drawdown in a hair-raising, eight-part series of NewsMax exposes in March 1999.
The drawdown of strategic missiles—mostly land-based ones for the United States—had radically reduced the number of available warheads, and, like planners everywhere, the Joint Strategic Targeting Staff, co-located with headquarters SAC, tried to make up for the shortfall in any way they could.