Construction

Construction is the process of creating and building infrastructure or a facility. It differs from manufacturing in that manufacturing typically involves mass production of similar items without a designated purchaser, while construction is typically done on location for a known client. Construction as an industry is six to nine percent of the gross domestic product of developed countries. Construction starts with planning, design, and financing and continues until the project is built and ready for use.

Large scale construction is an example of human multitasking. An architect normally manages the job, and a construction manager, design engineer, construction engineer or project manager supervises it. For the successful execution of a project, effective planning is essential. Those involved with the design and execution of the infrastructure in question must consider the zoning requirements, the environmental impact of the job, the successful scheduling, budgeting, construction site safety, availability and transportation of building materials, logistics, inconvenience to the public caused by construction delays and bidding, etc.

Algebraic K-theory

Algebraic K-theory is a subject area in mathematics with connections to geometry, topology, ring theory, and number theory. Geometric, algebraic, and arithmetic objects are assigned objects called K-groups. These are groups in the sense of abstract algebra. They contain detailed information about the original object but are notoriously difficult to compute; for example, an important outstanding problem is to compute the K-theory of the integers.

K-theory was discovered in the late 1950s by Alexander Grothendieck in his study of intersection theory on algebraic varieties. Intersection theory is still a motivating force in the development of algebraic K-theory through its links with motivic cohomology and specifically Chow groups. The subject also includes classical number-theoretic topics like quadratic reciprocity and embeddings of number fields into the real numbers and complex numbers, as well as more modern concerns like the construction of higher regulators and special values of L-functions.

Construction (Cage)

Construction is the title of several pieces by American composer John Cage, all scored for unorthodox percussion instruments. The pieces were composed in 1939–42 while Cage was working at the Cornish School of the Arts in Seattle, Washington and touring the West Coast with a percussion ensemble he and Lou Harrison had founded. The series comprises three Constructions. A piece titled Fourth Construction, mentioned in several sources, is apparently either an unfinished work from 1942 or, more likely, an early title of the work we now know as Imaginary Landscape No. 2 (March).

First Construction (in Metal)

First Construction (in Metal) was composed in 1939; its first title was Construction in Metal. Scored for six percussionists and an assistant. Instruments include, among other things, Japanese and Balinese gongs, Chinese and Turkish cymbals, automobile brake drums, anvils and a water gong (a gong lowered into water while vibrating, or struck while it is in the water, etc.) A piano is also used, with the assistant applying a metal rod to the strings.