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Response surface methodology (RSM) is used to express stress and displacement constraints in the linear form with respect to design variables. The objective function of minimizing the weight of truss structure is transformed into a second-order form. The original model is formulated as a standard QP model. Sensitivity analyses by RSM and Mohr integration are compared. An example is presented to illustrate the effectiveness and efficiency of RSM in application to truss optimization. [ABSTRACT FROM AUTHOR]

Response surface methodology (RSM) is a method to solve sensitivity of objective and constraints approximately in structural optimization. The errors between the fitting values and the structural responses at the design points will affect the precision of optimization. This paper provides an improved method that fit accurately at some design point. Two numerical examples illustrate its feasibility and efficiency. [ABSTRACT FROM AUTHOR]

Meridian-collateral knowledge is a profound and complex part of the whole traditional Chinese medicine (TCM). It is the basis for many TCM-related computer applications. This work aimed to develop a sharable knowledge base of the human meridian-collateral system for those applications. We began the work by building a frame ontology of the meridian-collateral system (called OMCAP); and then developed a large-scale sharable instance base (called IMCAP), which was, with the aid of the tool OKEE. The OMCAP consists of 89 categories and 38 slots, and the IMCAP contains 1549 instance frames. [ABSTRACT FROM AUTHOR]

Numerical simulation of a Czochralski crystal growth is a very helpful tool in optimizing the real experiment to produce high-quality single crystals in microelectronic industry. With the increase of silicon crystal size by Czochralski method, the melt volumes and the corresponding crucible diameters have to increase as well, which make the melt flows become more and more turbulent, laminar model is no longer suitable, so a low-Reynolds number k -ɛ model of Jones and Launder considered Lorentz force were used to describe a large-scale crystal growth process in this paper. The SIMPLE algorithm was employed to couple velocity and pressure field. A finite volume method was employed and a staggered grid arrangement was used to avoid zigzag pressure field. A third order QUICK (Quadratic Upwind Interpolation of Convective Kinematics) was used to discretize the convection term in the governing equations. In order to get low defects crystal ingot, the growth interface should be kept flat or slightly concave. This means that the isotherm at the growth interface is approximately perpendicular to the growth direction, the isotherm should be flatter, and the small temperature gradient at the interface is suitable. While the temperature gradient is strongly influenced by the flow pattern in the crucible, the strength of the magnetic field, the crystal and crucible rotations are the three major factors in determining the melt flow pattern, in this study, we aim at optimizing this three design variable to control the temperature gradient at the interface. Concepts and techniques of response surface methodology (RSM) have been widely applied in many branches of engineering, especially in the chemical and manufacturing areas. The basic idea of RSM is to approximate the actual state function, which may be implicit and/or very time-consuming to evaluate, with the so-called response surface function that is easier to deal with complex problem. This paper presents an application of the methodology with a turbulence model to optimize the temperature gradient. The simulation demonstrates that the response surface methodology is a feasible algorithm for the optimization of the Czochralski crystal growth process. [ABSTRACT FROM AUTHOR]

It is well known that topology optimization of 3D continuum structure is one of the major challenges because of difficulty to establish a good geometric model which comprising a large number of design variables, and complexity of optimization algorithm. On the other hand, the problem under multiple load case is not easy to be approached than one under single load case, because the former becomes a multiple objective problem based on compliance objective function. In order to overcome these difficulties, the optimal topology model of 3D continuum structure is established based on ICM (Independent Continuous Mapping) method, which refers to weight as objective and subjected to stress constraints and displacement constraints with multi-load-cases. A globalization of stress constraints is proposed by virtue of the von Mises' yield criteria in theory of elastic failure. Thus, transformation of all elements' stress constraints into a structural energy constraint is achieved, namely, a global constraint substitutes for lots of local constraints. As a result, the numbers of constraints is reduced, and the complexity of the sensitivity analysis is decreased. For global displacement constraints, an explicit expression of displacement with respect to the topological variables is formulated by using of unit virtual load method. In order to decrease the error of numerical calculation generated by the order magnitude between different physical quantities, the optimal model that normalizes with two types of dimensionless constraints is further derived for continuum structure with stress constraints and displacement constraints. Furthermore, the best path transmitted force in the multiple load cases is selected successfully. The dual quadratic programming is applied for to solve the optimal model of continuum. Consequently, the number of design variables is dramatically decreased; the efficiency of computation is improved. In addition, the present optimal model and its algorithm have been implemented by means ofthe MSC/Patran software platform using PCL. Several numerical examples indicate that the method is effective and efficient. As an example, Figure 1 illustrates the background structure of an elastic body with size 10×0. 6×2m3. The two corner points on the bottom side are fixed. Four central forces P1 = P2 = P3 = P4 = 450 kN are located in the middle of top of beam. The allowable stress is 50 Mpa, and the displacement constraint value of the four nodal points where the forces are located is less than 0.8 mm along with the up-to-down direction. The optimal topology configuration of the structures is illustrated in Figure 2. [ABSTRACT FROM AUTHOR]