Abstract: A temperature calculation method for a substrate, the temperature calculation method includes: calculating, by a computer performing a circuit simulation based on a resistance equivalent to a component that joins two substrates included in a target model of an analysis, a value of a current that flows through the component or voltage values in respective end portions of the component; setting, based on model information for expressing the target model, the current value or the voltage values in a first surface and a second surface that are included in surfaces of an outer shape of the component and that are in contact with the respective substrates; and calculating a first current density distribution of the component by performing a first electrical analysis according to the setting.

Abstract: A processing unit generates a first graph that has a plurality of vertices respectively corresponding to all variables included in an objective function and has edges each connecting two vertices to indicate an existence of interaction between corresponding variables, generates a second graph, which is an abstraction of the first graph, by repeatedly merging two vertices connected by an edge into one vertex in the first graph, classifies all variables into candidates for variable groups to be respectively used for partial problems and a candidate for a boundary variable group to be used for computing a complete solution to a combinatorial optimization problem, based on the connection relationship among a plurality of vertices included in the second graph and a partition count, and determines the variable groups and boundary variable group, based on these candidates by reference to the connection relationship among the vertices included in the first graph.

Abstract: An internal combustion engine is provided, in which a quantity of NOx emission can be reduced without using any special components even when a NOx reduction catalyst has an elevated temperature due to high-load operation. The internal combustion engine includes an engine, a three-way catalyst and a NOx reduction catalyst for purifying exhaust gas emitted from the engine, a temperature sensor for acquiring the temperature of the NOx reduction catalyst, a rotation speed sensor for acquiring an engine rotation speed, an injection controller for controlling a fuel injection quantity in the engine, and a combustion switching controller for switching a combustion mode of the engine between lean and stoichiometric combustion modes based on the NOx reduction catalyst temperature, the engine rotation speed, and the fuel injection quantity acquired from the fuel injection controller.

Abstract: A non-transitory computer-readable recording medium has stored therein a program for causing a computer to execute a process for displaying a characteristic, the process includes displaying, on a display, a main screen indicating a first characteristic in a first area of an object to be analyzed; and displaying, on the display, a sub-screen indicating a second characteristic in a second area in the object, the second characteristic being different from the first characteristic, the second area being specified within the main screen, the sub-screen being overlapped on a portion within the main screen, the portion being corresponding to a portion of the second area in the first area.

Abstract: A non-transitory computer-readable recording medium having stored therein a program for causing a computer to execute a process for thermal conductivity calculation, the process includes receiving information indicating a surface of a first part, on which a particular part having high elasticity is disposed; receiving specification information indicating a second part in contact with the particular part; receiving information Indicating a first thickness of the particular part; calculating a second thickness of the particular part after compressed when the particular part is placed between the surface and the second part; and calculating a thermal conductivity of the compressed particular part having the second thickness, according to an amount of compression indicating a difference between the first and the second thicknesses and to a correspondence relationship between a thermal resistance of the particular part and an amount obtained by subtracting a thickness of the compressed particular part from the fir

Abstract: A temperature calculation method for a substrate, the temperature calculation method includes: calculating, by a computer performing a circuit simulation based on a resistance equivalent to a component that joins two substrates included in a target model of an analysis, a value of a current that flows through the component or voltage values in respective end portions of the component; setting, based on model information for expressing the target model, the current value or the voltage values in a first surface and a second surface that are included in surfaces of an outer shape of the component and that are in contact with the respective substrates; and calculating a first current density distribution of the component by performing a first electrical analysis according to the setting.

Abstract: A disclosed setting method includes: in response to an instruction to replace a first component with a second component, determining whether or not data that correlates a surface of the first component with a surface of a third component has been set; upon determining that the data that correlates the surface of the first component with the surface of the third component has been set, extracting a surface of the second component, which corresponds to the surface of the first component; and correlating the extracted surface of the second component with the surface of the third component instead of the surface of the first component in the data.

Abstract: A disclosed setting method includes: in response to an instruction to replace a first component with a second component, determining whether or not data that correlates a surface of the first component with a surface of a third component has been set; upon determining that the data that correlates the surface of the first component with the surface of the third component has been set, extracting a surface of the second component, which corresponds to the surface of the first component; and correlating the extracted surface of the second component with the surface of the third component instead of the surface of the first component in the data.

Abstract: In a gas-mixture-nonuniformity acquisition apparatus for an internal combustion engine, the nonuniformity of fuel concentration within a gas mixture is acquired under the assumption that, in a process in which a cylinder interior gas taken into a combustion chamber of the engine and fuel injected into the combustion chamber mix together to form a gas mixture, a collision reaction repeatedly takes place within the gas mixture in such a manner that, due to collision of two gas volumes having different fuel mass ratios, respective portions of the two gas volumes mix together, and the mixed portions separate from the corresponding gas volumes and form a portion or the entirety of another gas volume having a fuel mass ratio different from those of the two gas volumes.

Abstract: In a gas-mixture-nonuniformity acquisition apparatus for an internal combustion engine, the nonuniformity of fuel concentration within a gas mixture is acquired under the assumption that, in a process in which a cylinder interior gas taken into a combustion chamber of the engine and fuel injected into the combustion chamber mix together to form a gas mixture, a collision reaction repeatedly takes place within the gas mixture in such a manner that, due to collision of two gas volumes having different fuel mass ratios, respective portions of the two gas volumes mix together, and the mixed portions separate from the corresponding gas volumes and form a portion or the entirety of another gas volume having a fuel mass ratio different from those of the two gas volumes.

Abstract: A gas-mixture-ignition-time estimation apparatus for an internal combustion engine estimates the temperature of a premixed gas mixture for PCCI combustion (i.e., cylinder interior temperature Tg), while relating it to the angle CA, on the basis of a state quantity of the cylinder interior gas at the time of start of compression (CAin) (heat energy of the cylinder interior gas at the time of start of compression), the amount of a change in the state quantity of the cylinder interior gas attributable to compression in a compression stroke (minute piston work), and the heat generation quantity of a cool flame generated in PCCI combustion prior to autoignition (hot flame) (cool flame heat generation quantity Aqlto). A time when the cylinder interior temperature Tg reaches a predetermined autoignition start temperature Tig is estimated as an autoignition start time (Caig) of the premixed gas mixture related to PCCI combustion.

Abstract: A gas-mixture-ignition-time estimation apparatus for an internal combustion engine estimates the temperature of a premixed gas mixture for PCCI combustion (i.e., cylinder interior temperature Tg), while relating it to the angle CA, on the basis of a state quantity of the cylinder interior gas at the time of start of compression (CAin) (heat energy of the cylinder interior gas at the time of start of compression), the amount of a change in the state quantity of the cylinder interior gas attributable to compression in a compression stroke (minute piston work), and the heat generation quantity of a cool flame generated in PCCI combustion prior to autoignition (hot flame) (cool flame heat generation quantity Aqlto). A time when the cylinder interior temperature Tg reaches a predetermined autoignition start temperature Tig is estimated as an autoignition start time (Caig) of the premixed gas mixture related to PCCI combustion.

Abstract: Cylinders of a diesel engine 1 are provided with cylinder pressure sensors 29a to 29d for detecting combustion chamber pressures. An electronic control unit (ECU) 20 of the engine selects optimum combustion parameters in accordance with a fuel injection mode of fuel injectors 10a to 10d of the engine and a combustion mode determined by the amount of EGR gas supplied from the EGR valve 35 from among a plurality of types of combustion parameters expressing the combustion state of the engine calculated based on the cylinder pressure sensor output and feedback controls the fuel injection amount and fuel injection timing so that the values of the combustion parameters match target values determined in accordance with the engine operating conditions. Due to this, the engine combustion state is controlled to the optimum state at all times regardless of the fuel injection mode or combustion mode.

Abstract: Cylinders of a diesel engine 1 are provided with cylinder pressure sensors 29a to 29d for detecting combustion chamber pressures. An electronic control unit (ECU) 20 of the engine selects optimum combustion parameters in accordance with a fuel injection mode of fuel injectors 10a to 10d of the engine and a combustion mode determined by the amount of EGR gas supplied from the EGR valve 35 from among a plurality of types of combustion parameters expressing the combustion state of the engine calculated based on the cylinder pressure sensor output and feedback controls the fuel injection amount and fuel injection timing so that the values of the combustion parameters match target values determined in accordance with the engine operating conditions. Due to this, the engine combustion state is controlled to the optimum state at all times regardless of the fuel injection mode or combustion mode.

Abstract: A state of combustion in a combustion chamber is controlled by stratifying an intake gas charge within the combustion chamber, so as to reduce amounts of harmful substances left in exhaust gas. A direct-injection type internal combustion engine in which a fuel is injected into the combustion chamber and which is arranged to stratify the intake gas charge within the combustion chamber (1) such that intake gases of different compositions exist in a central portion (13) of the combustion chamber including a position of the fuel injection, and in a peripheral portion of the combustion chamber, upon initiation of combustion of the fuel at a point of time near a terminal period of a compression stroke. The intake gases of different compositions may be intake gases having different concentrations of a specific component such as recirculated exhaust gas and the fuel.

Abstract: A state of combustion in a combustion chamber is controlled by stratifying an intake gas charge within the combustion chamber, so as to reduce amounts of harmful substances left in exhaust gas. A direct-injection type internal combustion engine in which a fuel is injected into the combustion chamber and which is arranged to stratify the intake gas charge within the combustion chamber (1) such that intake gases of different compositions exist in a central portion (13) of the combustion chamber including a position of the fuel injection, and in a peripheral portion of the combustion chamber, upon initiation of combustion of the fuel at a point of time near a terminal period of a compression stroke. The intake gases of different compositions may be intake gases having different concentrations of a specific component such as recirculated exhaust gas and the fuel.

Abstract: A direct-injection diesel engine in which a shallow-dish type piston cavity is formed on a top surface of a piston; wherein in the vicinity of the top dead center, a squish area is defined mainly by the top surface of the piston and an inner surface of a cylinder head opposite the top surface; when a velocity of a reverse squish flow from the shallow-dish type piston cavity to the squish area, generated due to a movement of the piston and is represented by Vs, and a fuel spray velocity in the vicinity of a lip portion of the shallow-dish type piston cavity is represented by Vsp, the distance between opposite wall portions of the shallow-dish type piston cavity is set such that the ratio Vs/Vsp is not greater than 1.25; and the squish area constitutes a part of the combustion chamber.