Thermal conductivity common use in the construction and textile industries. The construction industry makes use of units such as the R-value (resistance) and the U-value (transmittance). Although related to the thermal conductivity of a material used in an insulation product, R- and U-values are dependent on the thickness of the product. Likewise the textile industry has several units including the tog and the clo which express thermal resistance of a material in a way analogous to the R-values used in the construction industry. There are a number of ways to measure thermal conductivity. Each of these is suitable for a limited range
Compactness measure of a shape One example of a compactness measure is sphericity formula_1. Another measure in use is formula_2, which is proportional to formula_3. The Polsby-Popper Test is a mathematical measure of compactness that was developed to quantify the degree of gerrymandering of political districts. A common use of compactness measures is in redistricting. The goal is to maximize the compactness of electoral districts, subject to other constraints, and thereby to avoid gerrymandering. Another use is in zoning, to regulate the manner in which land can be subdivided into building lots. Another use is in pattern classification projects so that you can classify the