R-value (insulation) as ASHRAE 90.1 and the IECC prescribe U-values. However, R-value is widely used in practice to describe the thermal resistance of insulation products, layers, and most other parts of the building enclosure (walls, floors, roofs). Other areas of the world more commonly use U-value/U-factor for elements of the entire building enclosure including windows, doors, walls, roof, and ground slabs. The SI (metric) unit of R-value is whereas the I-P (inch-pound) unit is For R-values there is no difference between US customary units and imperial units, so the same I-P unit is used in both. Some sources use ″RSI″ when referring
Quality of results accepted as a good quality of result – relative density of combinational logic component – while a relative density of fifty will indicate severe design problems (routability, technology that is being used, etc.) which should be investigated and addressed. "Note:" A new term "Quality of Silicon" (QoS) is being promoted by the EDA industry in an attempt to measure the performance of backend EDA tools, like Xilinx ISE from Xilinx, or tools from Synopsys or Cadence Design Systems in isolation from the human designer's own performance in the frontend design stage. It is claimed that for historical reasons QoR is,