PDF Publication Title:
Text from PDF Page: 060
An Overview of Cost-Estimating Methods 43 these variables are frequently determined using a statistical tech- nique, such as ordinary least-squares (OLS) regression. The parametric relationships used for estimating costs are CERs. OLS can be applied to functional forms that are linear combinations of the explanatory variables. The functional form most often used in parametric methods is the “double log” or “log-log” form.1 The for- mat of a parametric relationship is lnY=bo +ÂbilnXi+e i where b0 and bi are coefficients, Xi are parameters (i.e., independent variables), and Y is the outcome or the dependent variable. This form is based on the assertion that errors are normally distributed in log space and not in real space. Using least-squares regression requires the residuals to be normally distributed with constant variance. A log-log relationship implies that our uncertainty in a predicted value is relative and not absolute. In other words, a forecast would be plus or minus a percentage value (rather than plus or minus some fixed dollar value) so that the error scales with the magnitude of the fore- cast. Parametric analysis has some strong advantages for estimating costs and the duration of development schedules. Its principal advantage is that after the basic parametric estimating relationship has been defined, applying the method is straightforward. Further, the analyst is not required to be a technical expert; however, to apply the method, the analyst must obtain values for all input parameters. Un- like the previous two approaches, a detailed conceptual design is not necessary to employ this method. Another, more subtle, advantage of parametric relationships generated using OLS regression is that one can also generate information on uncertainty of the forecasted value. In other words, one can obtain a result of y ± e where e is related to the error terms of the regression. This uncertainty value can be just as informative as the predicted value. ______________ 1The double log form is the most commonly used functional form that is nonlinear in the variable while still being linear in the coefficients.PDF Image | Military Jet Engine Acquisition Technology Basics and Cost-Estimating Methodology
PDF Search Title:
Military Jet Engine Acquisition Technology Basics and Cost-Estimating MethodologyOriginal File Name Searched:
MR1596.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |