A similarity matrix is a matrix of scores which express the similarity between two data points. Similarity matrices are strongly related to their counterparts, distance matrices and substitution matrices. Use in sequence alignment Similarity matrices are used in sequence alignment. Higher scores are given to more-similar characters, and lower or negative scores for dissimilar characters. Nucleotide similarity matrices are used to align nucleic acid sequences. Because there are only four nucleotides commonly found in DNA (Adenine (A), Cytosine (C), Guanine (G) and Thymine (T)), nucleoti...

Haar-like features are digital image features used in object recognition. They owe their name to their intuitive similarity with Haar wavelets and were used in the first real-time face detector. Historically, working with only image intensities (i.e., the RGB pixel values at each and every pixel of image) made the task of feature calculation computationally expensive. A publication by Papageorgiou et al. discussed working with an alternate feature set based on Haar wavelets instead of the usual image intensities. Viola and Jones adapted the idea of using Haar wavelets and developed the so-...

The Viola–Jones object detection framework is the first object detection framework to provide competitive object detection rates in real-time proposed in 2001 by Paul Viola and Michael Jones. Although it can be trained to detect a variety of object classes, it was motivated primarily by the problem of face detection. This algorithm is implemented in OpenCV as cvHaarDetectObjects(). Components of the framework Feature types and evaluation The features employed by the detection framework universally involve the sums of image pixels within rectangular areas. As such, they bear some rese...

Oi! is a subgenre of punk rock that originated in the United Kingdom in the late 1970s. The music and its associated subculture had the goal of bringing together punks, skinheads and other working-class youths (sometimes called herberts). The Oi! movement was partly a response to the perception that many participants in the early punk rock scene were, in the words of The Business guitarist Steve Kent, “trendy university people using long words, trying to be artistic...and losing touch”. André Schlesinger, singer of The Press, said, “Oi shares many similarities with folk music, beside...

Oy vey (), oy vay, or just oy — or even more elaborately oy vey iz mir, [http://en.wiktionary.org/wiki/oy_vey oh weh!] — is an exclamation of dismay or exasperation meaning something like "oh, [http://en.wiktionary.org/wiki/Weh pain]" or "woe is me". Derivation According to etymologist Douglas Harper, the phrase is derived from Yiddish and is of Germanic origin. It is a cognate of the German expression Oh weh, or Au weh, a common expression used in Bavaria and Austria in similar situations, combining the German and Dutch exclamation Au! meaning "Ouch/Oh" and the German word Weh, a cognate...