Body modificationBody modification (or body alteration) is the deliberate altering of the human anatomy or human physical appearance. In its broadest definition it includes skin tattooing, socially acceptable decoration (e.g., common ear piercing in many societies), and religious rites of passage (e.g., circumcision in a number of cultures), as well as the modern primitive movement.
Body artBody art is art made on, with, or consisting of, the human body. Body art covers a wide spectrum including tattoos, body piercings, scarification, and body painting. Body art may include performance art, body art is likewise utilized for investigations of the body in an assortment of different media including painting, casting, photography, film and video. More extreme body art can involve mutilation or pushing the body to its physical limits.
Robust statisticsRobust statistics are statistics with good performance for data drawn from a wide range of probability distributions, especially for distributions that are not normal. Robust statistical methods have been developed for many common problems, such as estimating location, scale, and regression parameters. One motivation is to produce statistical methods that are not unduly affected by outliers. Another motivation is to provide methods with good performance when there are small departures from a parametric distribution.
Field researchField research, field studies, or fieldwork is the collection of raw data outside a laboratory, library, or workplace setting. The approaches and methods used in field research vary across disciplines. For example, biologists who conduct field research may simply observe animals interacting with their environments, whereas social scientists conducting field research may interview or observe people in their natural environments to learn their languages, folklore, and social structures.
Prime numberA prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself. However, 4 is composite because it is a product (2 × 2) in which both numbers are smaller than 4.
SecularismSecularism is the principle of seeking to conduct human affairs based on naturalistic considerations, uninvolved with religion. Secularism is most commonly defined as the separation of religion from civil affairs and the state, and may be broadened to a similar position seeking to remove or to minimize the role of religion in any public sphere. The term "secularism" has a broad range of meanings, and in the most schematic, may encapsulate any stance that promotes the secular in any given context.
Secular ethicsSecular ethics is a branch of moral philosophy in which ethics is based solely on human faculties such as logic, empathy, reason or moral intuition, and not derived from belief in supernatural revelation or guidance—a source of ethics in many religions. Secular ethics refers to any ethical system that does not draw on the supernatural, and includes humanism, secularism and freethinking. A classical example of literature on secular ethics is the Kural text, authored by the ancient Indian philosopher Valluvar.
13 (number)13 (thirteen) is the natural number following 12 and preceding 14. Strikingly folkloric aspects of the number 13 have been noted in various cultures around the world: one theory is that this is due to the cultures employing lunar-solar calendars (there are approximately 12.41 lunations per solar year, and hence 12 "true months" plus a smaller, and often portentous, thirteenth month). This can be witnessed, for example, in the "Twelve Days of Christmas" of Western European tradition. The number 13 is the sixth prime number.
Central tendencyIn statistics, a central tendency (or measure of central tendency) is a central or typical value for a probability distribution. Colloquially, measures of central tendency are often called averages. The term central tendency dates from the late 1920s. The most common measures of central tendency are the arithmetic mean, the median, and the mode. A middle tendency can be calculated for either a finite set of values or for a theoretical distribution, such as the normal distribution.
Smooth numberIn number theory, an n-smooth (or n-friable) number is an integer whose prime factors are all less than or equal to n. For example, a 7-smooth number is a number whose every prime factor is at most 7, so 49 = 72 and 15750 = 2 × 32 × 53 × 7 are both 7-smooth, while 11 and 702 = 2 × 33 × 13 are not 7-smooth. The term seems to have been coined by Leonard Adleman. Smooth numbers are especially important in cryptography, which relies on factorization of integers.