Axiom of countable choiceThe axiom of countable choice or axiom of denumerable choice, denoted ACω, is an axiom of set theory that states that every countable collection of non-empty sets must have a choice function. That is, given a function A with domain N (where N denotes the set of natural numbers) such that A(n) is a non-empty set for every n ∈ N, there exists a function f with domain N such that f(n) ∈ A(n) for every n ∈ N. The axiom of countable choice (ACω) is strictly weaker than the axiom of dependent choice (DC), which in turn is weaker than the axiom of choice (AC).
Critical path methodThe critical path method (CPM), or critical path analysis (CPA), is an algorithm for scheduling a set of project activities. A critical path is determined by identifying the longest stretch of dependent activities and measuring the time required to complete them from start to finish. It is commonly used in conjunction with the program evaluation and review technique (PERT). The CPM is a project-modeling technique developed in the late 1950s by Morgan R. Walker of DuPont and James E. Kelley Jr. of Remington Rand.
Path (topology)In mathematics, a path in a topological space is a continuous function from the closed unit interval into Paths play an important role in the fields of topology and mathematical analysis. For example, a topological space for which there exists a path connecting any two points is said to be path-connected. Any space may be broken up into path-connected components. The set of path-connected components of a space is often denoted One can also define paths and loops in pointed spaces, which are important in homotopy theory.
Project networkA project network diagram is a graph that displays the order in which a project’s activities are to be completed. Derived from the work breakdown structure, the terminal elements of a project are organized sequentially based on the relationship among them. It is typically drawn from left to right to reflect project chronology. The Activity-on-Node (AON) technique uses nodes to represent individual project activities and path arrows to designate the sequence of activity completion.
Transportation demand managementTransportation demand management, traffic demand management or travel demand management (TDM) is the application of strategies and policies to reduce travel demand, or to redistribute this demand in space or in time. In transport, as in any network, managing demand can be a cost-effective alternative to increasing capacity. A demand management approach to transport also has the potential to deliver better environmental outcomes, improved public health, stronger communities, and more prosperous cities.
Discrete spaceIn topology, a discrete space is a particularly simple example of a topological space or similar structure, one in which the points form a , meaning they are isolated from each other in a certain sense. The discrete topology is the finest topology that can be given on a set. Every subset is open in the discrete topology so that in particular, every singleton subset is an open set in the discrete topology.
Time preferenceIn economics, time preference (or time discounting, delay discounting, temporal discounting, long-term orientation) is the current relative valuation placed on receiving a good or some cash at an earlier date compared with receiving it at a later date. Time preferences are captured mathematically in the discount function. The higher the time preference, the higher the discount placed on returns receivable or costs payable in the future. One of the factors that may determine an individual's time preference is how long that individual has lived.
Veterans DayVeterans Day (originally known as Armistice Day) is a federal holiday in the United States observed annually on November 11, for honoring military veterans of the United States Armed Forces (who were discharged under conditions other than dishonorable). It coincides with other holidays including Armistice Day and Remembrance Day which are commemorated in other countries that mark the anniversary of the end of World War I. Major hostilities of World War I were formally ended at the 11th hour of the 11th day of the 11th month of 1918 when the Armistice with Germany went into effect.
Metropolis light transportMetropolis light transport (MLT) is a global illumination application of a variant of the Monte Carlo method called the Metropolis–Hastings algorithm to the rendering equation for generating images from detailed physical descriptions of three-dimensional scenes. The procedure constructs paths from the eye to a light source using bidirectional path tracing, then constructs slight modifications to the path. Some careful statistical calculation (the Metropolis algorithm) is used to compute the appropriate distribution of brightness over the image.
Train stationA train station, railway station, railroad station, or railway depot is a railway facility where trains stop to load or unload passengers, freight, or both. It generally consists of at least one platform, one track, and a station building providing such ancillary services as ticket sales, waiting rooms, and baggage/freight service. If a station is on a single-track line, it often has a passing loop to facilitate traffic movements.
