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**EZ-FRISK™** contains a large number of programmed attenuation
equations along with their coefficients. The following standard equations are included:

- Abrahamson-Silva (1997, 2008 NGA)
- Akkar-Bommer (2007)
- Al-Tarazi and Qadan (1997)
- Ambraseyes (1996)
- Ambraseyes et. al. (2005)
- Amrat (1996)
- Atkinson (1997)
- Atkinson-Boore (1995, 1997, 2003, 2006)
- Atkinson-Kaka (2007)
- Atkinson-Motazedian (2002)
- Atkinson-Silva (2000)
- Atkinson-Sonley (2000)
- Bakun and Hopper (2004)
- Bakun, Johnston and Hopper (2003)
- Boore-Atkinson (2008) NGA
- Boore-Joyner-Fumal (1993, 1994, 1997)
- Campbell (1993, 1997, 2003)
- Campbell-Bozorgnia (1994, 2003, 2008 NGA)
- Chiou-Youngs (2008) NGA
- Crouse (1991)
- Frankel (1997)
- Fukushima-Tanaka (1992)
- Graizer-Kalkan (2007, 2009)
- Gregor (2002)
- Huo-Hu (2002)
- Idriss (1993, 2004, 2009)
- Kanno et. al. (2006)
- Malkawi-Fahmi (1996)
- McVerry et. al. (2006)
- Subetta-Pugliese (1996)
- Sadigh (1993, 1994, 1997)
- Silva et. al. (2002)
- Sommerville (2001, 2009)
- Spudich (1997, 1999)
- Tavakoli-Pezeshk (2005)
- Toro (1997, 1999)
- Traversou, Bray, Abrahamson (2003)
- Wald et. al. (1999)
- Youngs (1988, 1997)
- Zhao et. al. (2006)

**EZ-FRISK™** provides and supports attenuation equations that calculate:

- Horizontal, geometric mean spectral response at 5% damping
- Maximum rotated componsent of horizontal spectral response at 5% damping
- Vertical component of the spectral response at 5% damping
- PGV (Peak Ground Velocity)
- PGD (Peak Ground Displacement
- Arias Intensity
- MMI (Modified Mercalli Intensity)

The standard attenuation equation database includes variants for many modern
attenuation equations that use the *FEMA P-750/2009 Edition NEHRP Recommended Seismic Provisions*
method for calculating the **maximum rotated component** of ground motions. This helps user meet the
requirements of:

- DSA BULLETIN 09-01 from the California Division of the State Architect
- Code Application Notice 2-1802A.6.2 from the California Office of Statewide Health Planning and Development (OSHPD) .

The attenuation equation database can be used with any number of seismic hazard analyses. You can select one or more attenuation equations to use with each seismic source. You can also assign different equations to different sources. You can assign custom weights to each attenuation equation used with a source. For example, you can assign different attenuation equations to subduction zones then those used for your fault or gridded seismic sources. You can easily recalculate results if the attenuation equation database is updated.

**EZ-FRISK™** allows you to define your own custom attenuation equations, to implement
newly published or proprietary ground motion prediction equations. You can copy and modify existing
standard equations, or create completely new equations using an expression evaluator. When you use the
expression evaluator, you specify the predicted mean ground motion, as well as the log-normal standard
deviation using a simple formula syntax. These formulas can depend on any rupture metric calcuated by EZ-FRISK.
You can specify custom site parameters, as well as spectral-period and faulting-mechanism dependent coefficients.