Search results
Results From The WOW.Com Content Network
This matching may be assessed in the lung as a whole, or in individual or in sub-groups of gas-exchanging units in the lung. On the other side Ventilation-perfusion mismatch is the term used when the ventilation and the perfusion of a gas exchanging unit are not matched. The actual values in the lung vary depending on the position within the lung.
A ventilation/perfusion lung scan, also called a V/Q lung scan, or ventilation/perfusion scintigraphy, is a type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient's lungs, [1] [2] in order to determine the ventilation/perfusion ratio.
The lung structure is important for the mechanism of ventilation-perfusion coupling. Pleura (plural: pleurae) is a single membrane surrounding the lung. It folds back to form two layers, and each layer is called parietal pleura and visceral pleura.
Alpha-EM [5] ⊃ log-EM ⊃ basic competitive learning (vector quantization, VQ; or clustering). On the class of the vector quantization and competitive learning, he contributed to generate and identify the hierarchy of VQs. VQ ⇔ {batch mode VQ, and learning VQ} [8] ⊂ {harmonic competition} [7] ⊂ {multiple descent cost competition}. [8]
Vector quantization (VQ) is a classical quantization technique from signal processing that allows the modeling of probability density functions by the distribution of prototype vectors. Developed in the early 1980s by Robert M. Gray , it was originally used for data compression .
The precise origins of the positioning concept are unclear. Cano (2003), Schwartzkopf (2008), and others have argued that the concepts of market segmentation and positioning were central to the tacit knowledge that informed brand advertising from the 1920s, but did not become codified in marketing textbooks and journal articles until the 1950s and 60s.
Paul Keres ([ˈpɑu̯l ˈkeres]; 7 January 1916 – 5 June 1975) was an Estonian chess grandmaster and chess writer. He was among the world's top players from the mid-1930s to the mid-1960s, and narrowly missed a chance at a World Chess Championship match on five occasions.
The ICAO airport code is a four-letter alphanumeric code designating each airport around the world. It is defined by the International Civil Aviation Organization.