1. A method of simultaneously determining multiple parameters or a parameter distribution characterizing material properties of a volume of a subterranean formation under investigation using an inversion process of sparse measurements, the method comprising:
performing a potential field survey of the volume of the subterranean formation using sensors located around or within the volume;
defining a model of said volume and modifying said model by matching said multiple parameters or parameter distribution characterizing material properties with said measurements of the effects of the potential field using alternatingly an iterative inversion method and a probabilistic inversion method; and
determining said multiple parameters or parameter distribution characterizing material properties after one or more iterations of said alternating inversions wherein a pseudo-converged model obtained after one or more iterations of an inversion is transformed and the transformed model of the inversion is used as an input model for a successive inversion.
2. The method of claim 1, wherein after a probabilistic inversion, a most probable model of the probabilistic inversion is transformed and used as a starting model for the iterative inversion.
3. The method of claim 2, wherein the most probable model is selected as the model having the maximum probability.
4. The method of claim 1, wherein a first switching condition is associated with the iterative inversion method to switch to the probabilistic inversion method and a second switching condition is associated with said probabilistic inversion method to switch to said iterative inversion method.
5. The method of claim 1, wherein the iterations are terminated when a first termination condition is satisfied after the iterative inversion method and a second termination condition is satisfied after the probabilistic inversion method within one iteration of the alternating iterations.
6. The method of claim 1, wherein the number of iterations of said alternating inversions exceeds 4.
7. The method of claim 1, wherein the number of iterations of said alternating inversions exceeds 9.
8. The method of claim 1, wherein the alternating inversions continue until both the iterative inversion method and the probabilistic inversion method converge.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A valve assembly for an air brake system comprising:
a valve housing having a blind bore and a counter-bore;
a first valve member received in the blind bore having a first portion and a second portion forming an interference fit with the first portion; the first valve member comprising;
a check valve assembly interposed between the first and second portions and maintained in an assembled state within the first and second portions, the check valve assembly including a biasing member, a follower, and a check valve member; and
a second valve member received in the counter-bore of the valve housing, the first valve member and the second valve member in pneumatically operative communication with each other to provide a selected output from one of at least two pneumatic inputs.
2. A valve assembly for an air brake system comprising:
a valve housing having a bore;
a valve member received in the bore having a first portion and a second portion forming an interference fit with the first portion;
a check valve assembly interposed between the first and second portions and maintained in an assembled state within the first and second portions, the check valve assembly including a biasing member, a follower and a check valve member;
wherein the first portion includes a recess and the second portion includes protrusions extending therefrom and received in a friction fit engagement with the recess.
3. The valve assembly of claim 2 wherein the first portion of the valve member is formed from a non-metallic material.
4. The valve assembly of claim 2 wherein the second portion of the valve member is formed from a non-metallic material.
5. The valve assembly of claim 2 wherein the first portion of the valve member is formed from a non-metallic material and non-circular passages are provided therethrough to enhance flow.
6. A valve assembly comprising:
a housing having a blind ended bore formed therein and a counter-bore;
a first valve assembly dimensioned for receipt in the blind ended bore, the valve assembly including a first portion formed from a non-metallic material having at least one passage extending therethrough and having a recess formed at an open end thereof, and a second portion formed from a non-metallic material and including a surface dimensioned for interference fit with the recess, a check valve assembly received within the first and second portions including a spring, a spring follower, and a valve member disposed in abutting engagement within the first and second portions whereby the first valve assembly is maintained in assembled arrangement by the interference fit between the first and second portions allowing the first valve assembly to be easily inserted into the blind ended bore, and a second valve assembly received in the counter bore, the first valve assembly and the second valve assembly in pneumatically operative communication with each other.
7. A valve assembly comprising:
a housing having a blind opening formed therein;
a valve assembly dimensioned for receipt in the opening, the valve assembly including a first portion formed from a non-metallic material having at least one passage extending therethrough and having a recess formed at an open end thereof, and a second portion formed from a non-metallic material and including a surface dimensioned for interference fit with the recess, and a check valve assembly received within the first and second portions including a spring, a spring follower, and a valve member disposed in abutting engagement within the first and second portions whereby the valve assembly is maintained in assembled arrangement by the interference fit between the first and second portions allowing the valve assembly to be easily inserted into the blind opening; wherein the second portion includes raised protrusions disposed in spaced relation along the first portion for frictional engagement with the recess.
8. The assembly of claim 7 wherein the second portion includes a circumferentially continuous shoulder dimensioned for receipt in the recess.
9. A method of assembling a valve assembly, the method comprising the steps of:
providing a housing with a blind bore and associated opening therein;
providing a first non-metallic valve member portion having an open end defining a recess;
providing a second non-metallic valve member portion having a shoulder dimensioned for receipt in the recess of the first portion;
inserting a check valve assembly between the valve member first and second portions; and
frictionally engaging the shoulder in the recess to encase the check valve member between the first and second valve member portions and define a sub-assembly, wherein the housing is adapted to receive the sub-assembly.
10. The method of claim 9 comprising the further step of sealingly inserting the sub-assembly into the blind bore in the housing.
11. The method of claim 9 including the steps of placing the check valve assembly into a cavity in the second valve member portion and advancing the first and second portions toward one another prior to the fictional engagement step.