Abstract: For a plurality of combinations of a plurality of operating states included in an operating range of an engine and for a plurality of combinations of a plurality of objective variables, a system, which calculates design variables, includes a calculating device for obtaining global optimal solutions of the design variables that minimize or maximize a sum of the plurality of objective variables, which respectively correspond to the plurality of combinations of the plurality of operating states; a receiving device for receiving designation of an upper limit or a lower limit of the plurality of objective variables; and a searching device for searching for global optimal solutions that result in the smoothest change in the design variables when changing the operating states in a range of the received upper limit to the received lower limit of the objective variables, with one of the global optimal solutions as an initial value set.

Abstract: A method, computer, and recording medium storing a program are provided which, based on local optimal solutions, more efficiently calculate an optimal global optimal solution in a global operating area. System calculates the global optimal solution by solving, using a genetic algorithm based on the local optimal solutions and the initial values, an equation, which should be satisfied by the plurality of design variables, by obtaining the plurality of combinations of design variables composing local optimal solutions for each design variable respectively calculated for each of a plurality of combinations of a plurality of operating states, and by obtaining initial values for the plurality of combinations of design variables used for calculating the global optimal solution.

Abstract: For a plurality of combinations of a plurality of operating states included in an operating range of an engine and for a plurality of combinations of a plurality of objective variables, a system, which calculates design variables, includes a calculating device for obtaining global optimal solutions of the design variables that minimize or maximize a sum of the plurality of objective variables, which respectively correspond to the plurality of combinations of the plurality of operating states; a receiving device for receiving designation of an upper limit or a lower limit of the plurality of objective variables; and a searching device for searching for global optimal solutions that result in the smoothest change in the design variables when changing the operating states in a range of the received upper limit to the received lower limit of the objective variables, with one of the global optimal solutions as an initial value set.

Abstract: A method, computer, and recording medium storing a program are provided which, based on local optimal solutions, more efficiently calculate an optimal global optimal solution in a global operating area. System calculates the global optimal solution by solving, using a genetic algorithm based on the local optimal solutions and the initial values, an equation, which should be satisfied by the plurality of design variables, by obtaining the plurality of combinations of design variables composing local optimal solutions for each design variable respectively calculated for each of a plurality of combinations of a plurality of operating states, and by obtaining initial values for the plurality of combinations of design variables used for calculating the global optimal solution.