Simulation parameter determination method

• US 20070288175A1
• Filed: 05/30/2007
• Published: 12/13/2007
• Est. Priority Date: 05/30/2006
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ho, Shirun, Tobita, Motoi
• Granted Patent: US 7,729,892 B2
• Time in Patent Office: Days
• US Class Current: 702/22
• CPC Class Codes: G06F 2111/10 Numerical modelling
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30

Abstract

Provided is a method for reduction of calculation amount required for parameter determination, and for reduction of calculation amount required for parameter determination satisfying desired accuracy. It is a method for preferentially selecting analysis objects, which are capable of providing parameter determination in high degree of certainty, and for controlling calculation order of the selected analysis objects using a calculation order list.

Claims

1. A simulation parameter determination method, which is a method for elemental parameter determination necessary to reproduce, by simulation calculation, experimental value of characteristic value or property value measured on analysis objects of any of a plurality kinds of molecules, materials, parts or structures, each analysis object being composed of a plurality of one or a plurality of elements, each element being classified into one of a plurality kinds of elemental type s, or each element having one or a plurality of values of elemental attributes, wherein

(1) in the input step,

(1-1) acceptable error ε

that is maximum value acceptable to difference between calculated value obtained by simulation, and experimental value;

(1-2) convergence threshold τ

that is standard value to judge convergence of calculated value;

(1-3) information necessary for calculation of each analysis object, and experimental value for each analysis object; and

(1-4) elemental type for each element composing the analysis object, and value of elemental attribute of each element composing the analysis object are input into a memory unit,

(2) in the pre-processing step,

(2-1) value of elemental parameter by each elemental type is initialized; and

(2-2) a data set containing undetermined elemental parameter number on all of the analysis objects is present, and arrangement order of the data set is sorted up by the number of undetermined atomic parameters,

(3) in calculation order list generation step,

(3-1) an analysis object, having the number of undetermined elemental parameters of 1 or less, is selected from analysis objects containing undetermined elemental parameters; and

(3-2) a calculation order list is generated based on re-arranged order at the above (2-2), of the selected analysis objects, as calculation order,

(4) in the solving step of a one-variable equation,

(4-1) only in the case where an analysis object on the top of calculation order list contains undetermined elemental parameter, solving of a one-variable equation for determination of undetermined parameters is iterated until the amount of change of calculated value becomes below convergence threshold, to determine undetermined elemental parameter, and in the case where an analysis object on the top of calculation order list does not contain undetermined elemental parameter, process is forwarded to the following step (4-2);

(4-2) calculation error, that is difference between calculated value of said analysis object using determined elemental parameter and experimental value, is calculated;

(4-3) absolute value of said calculation error, and said acceptable error are compared;

(4-4) in the case where said calculation error is over the acceptable error, one of the tentatively determined elemental parameters is set newly as an undetermined elemental parameter to return to the step (4-1), and in the case where said calculation error is not over the acceptable error, process is forwarded to the following step (4-5); and

(4-5) in the case where said calculation error is equal to or below the acceptable error, a data set on the top position of calculation order list is deleted;

in the case where an analysis object is present on the top of calculation order list, process returns to the step (4-1); and

in the case where calculation order list is empty, process is forwarded to the step (5),

(5) in the elemental parameters update step,

(5-1) elemental parameter of corresponding elemental type is updated, as a function of value of elemental attribute, using an elemental parameter determined in the above one-variable equation solving step;

(5-2) some or all undetermined elemental parameters, which is classified to said elemental type, are tentatively determined, using a function describing value of elemental parameter of the updated elemental type;

(5-3) a plurality of data sets of analysis objects including undetermined elemental parameters are sorted up by the number of undetermined atomic parameters;

(5-4) subsequent to the above (5-3), analysis objects with the same number of undetermined atomic parameters are sorted down by the number of elemental parameters; and

(5-5) whether all of or at least some of each of parameters of the data sets including undetermined elemental parameters is determined or not, and

(6) whether undetermined analysis objects are present or not, is judged, and in the case where undetermined analysis objects are present, process returns to the above step (3), and

in the case where undetermined analysis objects are not present, process terminates.

2. A simulation parameter determination method, which is a method for elemental parameter determination necessary to reproduce, by simulation calculation, experimental value of characteristic value or property value measured on analysis objects of any of a plurality kinds of molecules, materials, parts or structures, each analysis object being composed of a plurality of one or a plurality of elements, each element being classified into one of a plurality kinds of elemental type s, or each element having one or a plurality of values of elemental attributes, wherein

(1) in the input step,

(1-1) convergence threshold τ

that is standard value to judge convergence of calculated value;

(1-2) three-dimensional coordinate information of elements composing the analysis object, necessary for calculation of experimental value for each analysis object, or experimental value for each analysis object; and

(1-3) elemental type for each element composing the analysis object, and value of elemental attribute of each element composing the analysis object are input into a memory unit,

(2) in the pre-processing step,

(2-1) value of elemental parameter by each elemental type is initialized; and

(2-2) a data set containing undetermined elemental parameter number on all of the analysis objects is present, and arrangement order of the data set is sorted up by the number of undetermined atomic parameters,

(3) in calculation order list generation step,

(3-1) an analysis object, having the number of undetermined elemental parameters of 1, is selected from analysis objects containing undetermined elemental parameters; and

(3-2) a calculation order list is generated based on re-arranged order at the above (2-2), of the selected analysis objects, as calculation order,

(4) in the solving step of a one-variable equation,

(4-1) on an analysis object on the top of calculation order list, solving of a one-variable equation for determination of undetermined parameters is iterated until the amount of change of calculated value becomes below convergence threshold, to determine undetermined elemental parameter; and

(4-2) a data set on the top position of calculation order list is deleted; and

in the case where an analysis object is present on the top of calculation order list, process returns to the step (4-1); and

in the case where calculation order list is empty, process is forwarded to the step (5),

(5) in the elemental parameters update step,

(5-1) elemental parameter of corresponding elemental type is updated, as a function of value of elemental attribute, using an elemental parameter determined in the above one-variable equation solving step;

(5-2) a plurality of data sets of analysis objects including undetermined elemental parameters are sorted up by the number of undetermined elemental parameters;

(5-3) subsequent to the above (5-2), analysis objects with the same number of undetermined elemental parameters are sorted down by the number of elemental parameters; and

(5-4) whether all of or al least some of each of parameters of the data sets of analysis objects including undetermined elemental parameters is determined or not, and

(6) whether undetermined analysis objects are present or not, is judged, and in the case where undetermined analysis objects are present, process returns to the above step (3), and in the case where undetermined analysis objects are not present, process terminates.

3. A simulation parameter determination method, which is a method for atomic parameter determination necessary to reproduce, by simulation calculation, experimental value of each solvation energy measured on a plurality kinds of molecules, each molecule being composed of a plurality of atoms, each atom being classified into one of a plurality kinds of atomic types, or each atom having one or a plurality of values of atomic attributes, wherein

(1) in the input step,

(1-1) acceptable energy error e that is maximum value acceptable to difference between calculated value of salvation energy obtained by simulation calculation, and experimental value of solvation energy;

(1-2) energy convergence threshold τ

that is standard value to judge convergence of calculated value of solvation energy;

(1-3) three-dimensional coordinate information of atoms composing the molecule, necessary for calculation of experimental value salvation energy for each molecule, or experimental value of solvation energy for each molecule; and

(1-4) atomic type for each atom composing the molecule, and value of an atomic attribute of each atom composing the molecule are input into a memory unit,

(2) in the pre-processing step,

(2-1) atomic parameter value by each atomic type is initialized; and

(2-2) a data set containing undetermined atomic parameter number on all of the molecules is present, and arrangement order of the data set is sorted up by the number of undetermined atomic parameters,

(3) in calculation order list generation step,

(3-1) a molecule, having the number of undetermined atomic parameters of 1 or less, is selected from molecules containing undetermined atomic parameters; and

(3-2) a calculation order list is generated based on re-arranged order at the above (2-2), of the selected molecules, as calculation order,

(4) in the solving step of a one-variable equation,

(4-1) only in the case where an molecule on the top of calculation order list contains undetermined atomic parameter, solving of a one-variable equation for determination of undetermined parameters is iterated until the amount of change of calculated value of solvation energy becomes below energy convergence threshold, to determine undetermined parameter, and in the case where a molecule on the top of calculation order list does not contain undetermined atomic parameter, process is forwarded to the following step (4-2);

(4-2) calculation error, that is difference between calculated value of said molecule using determined atomic parameter and experimental value, is calculated;

(4-3) absolute value of said calculation error, and said acceptable energy error are compared;

(4-4) in the case where said energy calculation error is over the acceptable energy error, one of the tentatively determined atomic parameters is set newly as an undetermined atomic parameter to return to the step (4-1), and in the case where said energy calculation error is not over the acceptable energy error, process is forwarded to the following step (4-5); and

(4-5) in the case where said calculation error is equal to or below the acceptable error, a data set on the top position of calculation order list is deleted;

in the case where a molecule is present on the top of calculation order list, process returns to the step (4-1); and

in the case where calculation order list is empty, process is forwarded to the step (5),

(5) in the atomic parameters update step,

(5-1) atomic parameter of corresponding atomic type is updated, as a function of value of an atomic attribute, using an atomic parameter determined in the above one-variable equation solving step;

(5-2) some or all of undetermined atomic parameters, which is classified to said atomic type, are tentatively determined, using a function describing atomic parameter value of the updated atomic type;

(5-3) a plurality of data sets of molecules including undetermined atomic parameters are sorted up by the number of undetermined atomic parameters;

(5-4) subsequent to the above (5-3), molecules with the same number of undetermined atomic parameters are sorted down by the number of atomic parameters; and

(5-5) whether all of or al least some of each of parameters of the data sets of molecules including undetermined atomic parameters is determined or not, and

(6) whether undetermined molecules are present or not, is judged, and in the case where undetermined molecules are present, process returns to the above step (3), and in the case where undetermined molecules are not present, process terminates.

5. The simulation parameter determination method according to claim 3, wherein user interface is provided with function that, in said calculation order list generation step, when calculation order is displayed, and one molecule in said calculation order is selected, an atomic distribution map at a plane formed by atomic charge and averaged bond distance, and a molecular structure map that expresses the atomic parameter determination status of said selected molecule, by a three-dimensional structure of the molecular, and spheres drawn on each atom composing the molecule, in an overlapped way, are displayed, as for an atomic type to which undetermined atomic parameter of said selected molecule is classified, and a user can change calculation order based on these sets of display information.

7. The simulation parameter determination method according to claim 3, wherein user interface is provided with function that, in said calculation order list generation step, after generation of calculation order list, or after a user executes re-arrangement or deletion of molecules in calculation order list, summary result of a calculation status of the molecule, such as “

value assigned”

, “

in progress”

, or “

undetermined”

, and calculation elapsed time are displayed, as summary of a progress of atomic parameter calculation, or a calculation status, the number of atomic parameters and the number of undetermined atomic parameters of each atom are displayed, as summary of a progress of atomic parameter of each atom.

9. The simulation parameter determination method according to claim 3, wherein user interface is provided with function that, in said atomic parameters update step, the number of all atoms, the number of atoms having determined atomic parameter, the number of tentatively determined atoms and the number of undetermined atoms are displayed by each atomic type, as the atomic parameter determination status of each atomic type, and when one atomic type is selected, an atomic parameter of an atom belonging to said atomic type is displayed in space formed by atomic charge, averaged bond distance and atomic parameter.

4. A simulation parameter determination method, which is a method for atomic parameter determination necessary to reproduce, by simulation calculation, experimental value of each solvation energy measured on a plurality kinds of molecules, each molecule being composed of a plurality of atoms, each atom being classified into one of a plurality kinds of atomic types, or each atom having one or a plurality of values of atomic attributes, wherein

(1) in the input step,

(1-1) energy convergence threshold τ

that is standard value to judge convergence of calculated value of solvation energy;

(1-2) three-dimensional coordinate information of atoms composing the molecule, necessary for calculation of experimental value salvation energy for each molecule, or experimental value of solvation energy for each molecule; and

(1-3) atomic type for each atom composing the molecule, and value of an atomic attribute of each atom composing the molecule are input into a memory unit,

(2) in the pre-processing step,

(2-1) atomic parameter value by each atomic type is initialized; and

(2-2) a data set containing undetermined atomic parameter number on all of the molecules is present, and arrangement order of the data set is sorted up by the number of undetermined atomic parameters,

(3) in calculation order list generation step,

(3-1) a molecule, having the number of undetermined atomic parameters of 1, is selected from molecules containing undetermined atomic parameters; and

(3-2) a calculation order list is generated based on re-arranged order at the above (2-2), of the selected molecules, as calculation order,

(4) in the solving step of a one-variable equation,

(4-1) solving of a one-variable equation for determination of undetermined parameters is iterated until the amount of change of calculated value of salvation energy becomes below convergence threshold, to determine undetermined parameter, on a molecule on the top of calculation order list; and

(4-2) a data set on the top position of calculation order list is deleted;

in the case where a molecule is present on the top of calculation order list, process returns to the step (4-1); and

in the case where calculation order list is empty, process is forwarded to the step (5),

(5) in the atomic parameters update step,

(5-1) atomic parameter of corresponding atomic type is updated, as a function of value of an atomic attribute, using an atomic parameter determined in the above one-variable equation solving step;

(5-2) a plurality of data sets of molecules including undetermined atomic parameters are sorted up by the number of undetermined atomic parameters;

(5-3) subsequent to the above (5-2), molecules with the same number of undetermined atomic parameters are sorted down by the number of atomic parameters; and

(5-4) whether all of or al least some of each of parameters of the data sets of molecules including undetermined atomic parameters is determined or not, and

(6) whether undetermined molecules are present or not, is judged, and in the case where undetermined molecules are present, process returns to the above step (3), and in the case where undetermined molecules are not present, process terminates.

6. The simulation parameter determination method according to claim 4, wherein user interface is provided with function that, in said calculation order list generation step, when calculation order is displayed, and one molecule in said calculation order is selected, an atomic distribution map at a plane formed by atomic charge and averaged bond distance, and a molecular structure map that expresses the atomic parameter determination status of said selected molecule, by a three-dimensional structure of the molecular, and spheres drawn on each atom composing the molecule, in an overlapped way, are displayed, as for an atomic type to which undetermined atomic parameter of said selected molecule is classified, and a user can change calculation order based on these sets of display information.

8. The simulation parameter determination method according to claim 4, wherein user interface is provided with function that, in said calculation order list generation step, after generation of calculation order list, or after a user executes re-arrangement or deletion of molecules in calculation order list, summary result of a calculation status of the molecule, such as “

value assigned”

, “

in progress”

, or “

undetermined”

, and calculation elapsed time are displayed, as summary of a progress of atomic parameter calculation, or a calculation status, the number of atomic parameters and the number of undetermined atomic parameters of each atom are displayed, as summary of a progress of atomic parameter of each atom.

10. The simulation parameter determination method according to claim 4, wherein user interface is provided with function that, in said atomic parameters update step, the number of all atoms, the number of atoms having determined atomic parameter, the number of tentatively determined atoms and the number of undetermined atoms are displayed by each atomic type, as the atomic parameter determination status of each atomic type, and when one atomic type is selected, an atomic parameter of an atom belonging to said atomic type is displayed in space formed by atomic charge, averaged bond distance and atomic parameter.