160results about How to "Calculation stable" patented technology

The invention relates to a CFD (computational fluid dynamics) based method for computing equivalent length of a valve. The method includes the steps: establishing a three-dimensional assembly model of the valve, after an extension section is added to an entry and exit position of the valve model, importing the model into CFD software, working out pressure values of multiple working conditions by analog calculation of the CFD software and computing corresponding pressure differences; according to the pressure differences, respectively computing multiple flow coefficient values through a formula, and then computing an average flow coefficient value; computing an equivalent length value of the valve through a formula. Flow performance data of the valve are obtained by the aid of CFD technological analogue simulation, only drawings are needed to be used for completion in a virtual prototype phase in the initial stage of development, and the situations that manpower and material resources are wasted and development cycle is prolonged due to the fact that the valve must be manufactured and subjected to test measurement in order to detect flow performance of the valve in the prior art are avoided, so that development efficiency is greatly improved and cost is saved by the method.

An image processing apparatus includes: an image obtaining device which obtains a breast image obtained by radiography of a breast; a mammary gland region extracting device which extracts a mammary gland region from the breast image; a local region setting device which sets a plurality of local regions around pixels belonging to the extracted mammary gland region; a local contrast value calculating device which calculates a plurality of local contrast values in a local regions, for each of the set plurality of local regions; and an image processing device which applies image processing to the breast image on the basis of the calculated plurality of local contrast values. Thus, considering a contrast between a mammary gland and a fat region, a stable image processing result can be obtained while enhancing viewability of a local mammary gland structure and a lesion.

The invention discloses a limited space constraint based dynamic co-simulation method of an injection manipulator. A structural model and a D-H model of the manipulator are established by structural expression driving function and a link function respectively, trajectory planning inverse motion solution is performed on the manipulator according to the initial position and the termination position of the manipulator, an initial trajectory curve and angle change curves of all joints are obtained, and all operations of a UG interface are compiled into a separate M function to be embedded in a dynamic simulation model of an MATLAB / Simulink module for fitting of a trajectory curve. The ideal trajectory which is continuous, smooth in joint and shorter in end motion time and meets actual demands under the condition of limited space constraint is obtained, a manipulator trajectory optimization method under the constraint of limited space is sought by combining co-simulation of structural dynamics and control system kinematics, and smooth driving of optimized trajectory joints is realized.

The invention discloses a method for computing accurate mirror symmetry of a three-dimensional complex model on the basis of internal implication transformation. The method includes interactively setting or computing rough symmetry planes of the model, transforming the given model according to the rough symmetry planes to enable the rough symmetry planes to coincide with a coordinate plane, and computing accurate symmetry planes according to internal implication transformation of a mirror symmetry model; transforming the model and the accurate symmetry planes to obtain accurate symmetry planes of original positions of the model. The method has the advantages that the method is based on strict internal implication transformation relations of the mirror symmetry model, the precision can be controlled, and the method is high in generalization performance and is widely applicable to the field of engineering application.

Disclosed herein is a program for calculating a displacement of a fluid comprising calculating the displacement with the fluid regarded as an elastic structural body for a given period of time.