Fluorescent lampA fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than an incandescent lamp. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output.
Standard errorThe standard error (SE) of a statistic (usually an estimate of a parameter) is the standard deviation of its sampling distribution or an estimate of that standard deviation. If the statistic is the sample mean, it is called the standard error of the mean (SEM). The sampling distribution of a mean is generated by repeated sampling from the same population and recording of the sample means obtained. This forms a distribution of different means, and this distribution has its own mean and variance.
Neo-conceptual artNeo-conceptual art describes art practices in the 1980s and particularly 1990s to date that derive from the conceptual art movement of the 1960s and 1970s. These subsequent initiatives have included the Moscow Conceptualists, United States neo-conceptualists such as Sherrie Levine and the Young British Artists, notably Damien Hirst and Tracey Emin in the United Kingdom, where there is also a Stuckism counter-movement and criticism from the 1970s conceptual art group Art and Language.
Post-conceptual artPost-conceptual, postconceptual, post-conceptualism or postconceptualism is an art theory that builds upon the legacy of conceptual art in contemporary art, where the concept(s) or idea(s) involved in the work takes some precedence over traditional aesthetic and material concerns. The term first came into art school parlance through the influence of John Baldessari at the California Institute of the Arts in the early 1970s.
Real estate developmentReal estate development, or property development, is a business process, encompassing activities that range from the renovation and re-lease of existing buildings to the purchase of raw land and the sale of developed land or parcels to others. Real estate developers are the people and companies who coordinate all of these activities, converting ideas from paper to real property. Real estate development is different from construction or housebuilding, although many developers also manage the construction process or engage in housebuilding.
Epigraph (mathematics)In mathematics, the epigraph or supergraph of a function valued in the extended real numbers is the set, denoted by of all points in the Cartesian product lying on or above its graph. The strict epigraph is the set of points in lying strictly above its graph. Importantly, although both the graph and epigraph of consists of points in the epigraph consists of points in the subset which is not necessarily true of the graph of If the function takes as a value then will be a subset of its epigraph For example, if then the point will belong to but not to These two sets are nevertheless closely related because the graph can always be reconstructed from the epigraph, and vice versa.
