Engineering and technology notes

Whole Earth Catalog – Wikipedia

Jovan Stosic December 8, 2017

The Whole Earth Catalog (WEC) was an American counterculture magazine and product catalog published by Stewart Brand several times a year between 1968 and 1972, and occasionally thereafter, until 1998. The magazine featured essays and articles, but was primarily focused on product reviews. The editorial focus was on self-sufficiency, ecology, alternative education, “do it yourself” (DIY), and holism, and featured the slogan “access to tools”. While WEC listed and reviewed a wide range of products (clothing, books, tools, machines, seeds, etc.), it did not sell any of the products directly. Instead, the vendor’s contact information was listed alongside the item and its review. This is why, while not a regularly published periodical, numerous editions and updates were required to keep price and availability information up to date.

https://en.m.wikipedia.org/wiki/Whole_Earth_Catalog

Mean opinion score

Jovan Stosic December 5, 2017

Mean opinion score (MOS) is a measure used in the domain of Quality of Experience and telecommunications engineering, representing overall quality of a stimulus or system. It is the arithmetic mean over all individual “values on a predefined scale that a subject assigns to his opinion of the performance of a system quality”.[1] Such ratings are usually gathered in a subjective quality evaluation test, but they can also be algorithmically estimated.
MOS is a commonly used measure for video, audio, and audiovisual quality evaluation, but not restricted to those modalities. ITU-T has defined several ways of referring to a MOS in Recommendation P.800.1, depending on whether the score was obtained from audiovisual, conversational, listening, talking, or video quality tests.

Source: Mean opinion score – Wikipedia