Density functional theoryDensity-functional theory (DFT) is a computational quantum mechanical modelling method used in physics, chemistry and materials science to investigate the electronic structure (or nuclear structure) (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases. Using this theory, the properties of a many-electron system can be determined by using functionals, i.e. functions of another function. In the case of DFT, these are functionals of the spatially dependent electron density.
Spatial planningSpatial planning mediates between the respective claims on space of the state, market, and community. In so doing, three different mechanisms of involving stakeholders, integrating sectoral policies and promoting development projects mark the three schools of transformative strategy formulation, innovation action and performance in spatial planning Spatial planning systems refer to the methods and approaches used by the public and private sector to influence the distribution of people and activities in spaces of various scales.
HistogramA histogram is an approximate representation of the distribution of numerical data. The term was first introduced by Karl Pearson. To construct a histogram, the first step is to "bin" (or "bucket") the range of values—that is, divide the entire range of values into a series of intervals—and then count how many values fall into each interval. The bins are usually specified as consecutive, non-overlapping intervals of a variable. The bins (intervals) must be adjacent and are often (but not required to be) of equal size.
Transport network analysisA transport network, or transportation network, is a network or graph in geographic space, describing an infrastructure that permits and constrains movement or flow. Examples include but are not limited to road networks, railways, air routes, pipelines, aqueducts, and power lines. The digital representation of these networks, and the methods for their analysis, is a core part of spatial analysis, geographic information systems, public utilities, and transport engineering.
Commercial areaCommercial areas in a city are areas, districts, or neighborhoods primarily composed of commercial buildings, such as a strip mall, office parks, downtown, central business district, financial district, "Main Street", or shopping centers. Commercial activity within cities includes the buying and selling of goods and services in retail businesses, wholesale buying and selling, financial establishments, and a wide variety of uses that are broadly classified as "business.
Widest path problemIn graph algorithms, the widest path problem is the problem of finding a path between two designated vertices in a weighted graph, maximizing the weight of the minimum-weight edge in the path. The widest path problem is also known as the maximum capacity path problem. It is possible to adapt most shortest path algorithms to compute widest paths, by modifying them to use the bottleneck distance instead of path length. However, in many cases even faster algorithms are possible.
AccidentAn accident is an unintended, normally unwanted event that was not directly caused by humans. The term accident implies that nobody should be blamed, but the event may have been caused by unrecognized or unaddressed risks. Most researchers who study unintentional injury avoid using the term accident and focus on factors that increase risk of severe injury and that reduce injury incidence and severity. For example, when a tree falls down during a wind storm, its fall may not have been caused by humans, but the tree's type, size, health, location, or improper maintenance may have contributed to the result.
Urban horticultureUrban horticulture is the science and study of the growing plants in an urban environment. It focuses on the functional use of horticulture so as to maintain and improve the surrounding urban area. Urban horticulture has seen an increase in attention with the global trend of urbanization and works to study the harvest, aesthetic, architectural, recreational and psychological purposes and effects of plants in urban environments. Horticulture and the integration of nature into human civilization has been a major part in the establishment of cities.
Urban cultureUrban culture is the culture of towns and cities. The defining theme is the presence of a large population in a limited space that follows social norms. This makes it possible for many subcultures close to each other, exposed to social influence without necessarily intruding into the private sphere. Globally, urban areas tend to hold concentrations of power, such as government capitals and corporate headquarters, and the wealthy and powerful people that are employed in them. Cities also organize people, create norms, beliefs, and values.
Crumple zoneCrumple zones, crush zones, or crash zones are a structural safety feature used in vehicles, mainly in automobiles, to increase the time over which a change in velocity (and consequently momentum) occurs from the impact during a collision by a controlled deformation; in recent years, it is also incorporated into trains and railcars. Crumple zones are designed to increase the time over which the total force from the change in momentum is applied to an occupant, as the average force applied to the occupants is inversely related to the time over which it is applied.
