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G&A-1 GLOSSARY AND ACRONYM LIST Airside--the part of an airport directly involved in the arrival and departure of aircraft. Black box--any device or process whose workings are not understood by or accessible to its user. CAD ( computer a ided de sign) -- software used to create precision architectural and engineering drawings or technical illustrations including geographic data management. Call statement--a line of software that calls another set of code, such as, function, procedure, or subroutine. Decision Analysis--a branch of science focused of problem solving by processes that break complicated decisions down into small pieces that can be dealt with individually and then recombine logically. Emissions--releases of gases to the atmosphere (e.g., the release of carbon dioxide during fuel combustion). Emissions can be either intended or unintended releases. Emission f actor--the rate at which pollutants are emitted into the atmosphere by one source or a combination of sources. Emission inventory--a list of air pollutants emitted into a communityâs, stateâs, nationâs, or the Earthâs atmosphere in amounts per some unit time (e.g. day or year) by type of source. An emission inventory has both political and scientific applications. End state--the ultimate conditions resulting from a course of events. Exogenous-- an action or object coming from outside a system Geometric spreading -- refers to the spreading of sound energy as a result of the expansion of the sound waves. GIS (geographic information systems)--a computer software program used to analyze spatial data that can be especially useful in examining noise distribution over a geographic area. Gold standard--a method, procedure, or measurement that is widely accepted as being the best available. Greenhouse g as--any gas that absorbs infrared radiation in the atmosphere. GHGs include, but are not limited to, water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrochlorofluorocarbons (HCFCs), ozone (O3), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Ground a bsorption--as sound propagates near the ground, ground absorption is the interaction of the sound wave with the ground that results in attenuation of the sound. Hard ground, such as water, has less attenuation than soft ground (most other surfaces). Also known as lateral attenuation. Interquartile Range (IRQ)-- a measure of statistical dispersion, being equal to the difference between the third and first quartiles. Isopleth--a continuous line on a map that represents some equal value. Isopollutant line-- A continuous line on a map that represents equal levels of a pollutant. Median--the middle value of an ordered set of values. Microscale--a scale of physical consideration or of bounds having a characteristic dimension typically under 1 mm. Microsoft . NET--is a software component of the Microsoft Windows operating system that provides a large body of pre-coded solutions to common program requirements, and manages the execution of programs written specifically for the framework. Mobile Source--a moving vehicle that emits pollutants. Such sources include airplanes, cars, trucks and ground support equipment.
G&A-2 Module-- A self-contained software program that carries out a clearly defined task and is intended to operate within a larger program suite. Monte Carlo test--a technique which obtains a probabilistic approximation to the solution of a problem by using statistical sampling techniques. Multiple Attribute Decision Models (MADM)--a discipline aimed at supporting decision makers who are faced with making numerous and conflicting evaluations with incomplete information; thus relying on indicators of the strength of various preferences. Noise contours--a continuous line on a map that represents equal levels of noise exposure. Noise hemispheres--noise data represented as the overall sound pressure levels on hemisphere of fixed radius around a source. Nonparametric st atistics--the branch of statistics dealing with variables without making assumptions about the form or the parameters of their distribution Post processor--additional software to organize the output from a computer model or models such that it is easily understandable. Reduced-order modeling--a function that approximates another function, but requiring mush less data. Rule based system--a way to store and manipulate knowledge to interpret information in a useful way. The system is composed of a list of rules and the actions to be taken for each. Run-time--time that it takes to run a software program. Screening t ool--in environmental modeling, refers to an easier to use version of a computer model to perform quick and conservative estimates of exposure and impact. Server-based--refers to running applications on the computer network server while forwarding the output to the users on the network. Simulation-based--is more general than time-step based in that other parameters than time can be used in the calculation process. Six Si gma M ethod--is a highly disciplined approach to decision making that helps people focus on improving processes to make them as near perfect as possible. The term six sigma describes a statistical measure of variation equal to 99.9997% accuracy. Sound p ressure level ( SPL)--is 10 times the base-10 logarithm of the ratio of the time-mean-square pressure of a sound, in a stated frequency band, to the square of the reference sound pressure in gases of 20 micropascals. Stakeholder--a person or entity that has an interest in the project and related outcomes and decisions. Transportation project stakeholders include the general public, manufacturers, contractors, operators, consultants, local authorities, state agencies, and Federal agencies, which are also referred as agency stakeholder or stakeholder agency. Steady-state--in environmental modeling, refers to calculations done in which several known variables are held constant. For example, aircraft modeling in FAAâs INM assumes that speed, thrust, and angle of flight are held constant along straight flight segments. Time-step ba sed s imulation--a modeling practice where simulation is accomplished by performing calculations for a defined time period, then advancing by a predefined time step and recalculating. This process is repeated to estimate the changes with time. Webinar--an interactive seminar conducted via the world-wide web.
G&A-3 ACRONYMS Abbreviations and acronyms used without definitions in TRB publications: AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACIâNA Airports Council InternationalâNorth America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA Air Transport Association ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers NASA National Aeronautics and Space Administration NASAO National Association of State Aviation Officials NCFRP National Cooperative Freight Research Program NCHRP National Cooperative Highway Research Program NHTSA National Highway Traffic Safety Administration NTSB National Transportation Safety Board SAE Society of Automotive Engineers SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (2005) TCRP Transit Cooperative Research Program TEA-21 Transportation Equity Act for the 21st Century (1998) TRB Transportation Research Board TSA Transportation Security Administration U.S.DOT United States Department of Transportation
