• 한국시뮬레이션학회논문지
• /
• 제4권1호
• /
• pp.75-86
• /
• 1995

There has been a great deal of interest in the area of group technology recently. They suggest that group technology's formation of cells of machines which are dedicated to production of families of parts will bring many of the advantages of cellular layout of job shops. In this context, Yoon [2] designed and suggested 3 types of the layout structure for a small firm, by introducing the cellular layout into the traditional flow line of an existing factory. Also he found that P5C, i.e. process layout /5 cells layout, outperformed the rest types. However, he performed the experiments in the standpoint of the existing factory operation and did not consider other operating methods including changing the dispatching and sequencing rules. Therefore, in this paper, we compared the performance of 3 different layout by the simulation technique using the real data from the existing factory, considering a newly suggested dispatching and machine selection rule.

• 건축역사연구
• /
• 제13권2호
• /
• pp.71-81
• /
• 2004

This paper discusses of the problem of direction and orientation of site design of a traditional Korean village. The research focus on how the directional orientation of each houses adapt the direction of the flow of surrounding mountains. The direction of mountains worked as a prime rule which most of the houses( 76.6%) observed the same direction as their own orientation. While the central part of the village followed the direction of mountains more strictly, however the houses on the periphery area tend to be more free from the direction of mountains. This houses of the periphery respect either the direction of the mountain flow right behind the house or faces toward the south.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1998년도 추계 학술대회논문집
• /
• pp.108-113
• /
• 1998

A numerical investigation for the flow, heat and mass transfer characteristics of the grooved evaporating tube with the films flowing down on both the inside and outside tube walls has been carried out. The condensation occurs along the outside wall while the evaporation takes place at the free surface of the inside film. The 3-D transport equations for momentum and energy are solved by using the FVM(Finite Volume Method). The free surface shape is tracked by the moving grid technique satisfying the SCL(Space Conservation Rule). Due to the secondary motion of the fluid, the film thins at the crest, while thickens at the valley. The velocity and temperature fields as well as the amounts of the condensed and evaporated mass have been successfully predicted for various operating conditions and groove shapes.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집B
• /
• pp.745-750
• /
• 2000

A numerical code which can simulate unsteady, incompressible and 3-dimensional flows in an engine cylinder has been developed. The governing equations based on the cylindrical coordinate are discretized by the finite volume method with staggered variable arrangements. A geometric conservation rule is also incorporated into the simulation code in order to deal with a moving boundary problem. For the unsteady simulation, a fractional step method is adopted. The law of wall is applied to the wall boundaries and standard $k-\;{\varepsilon}$ model is used to describe the in-cylinder turbulent flow. The model cylinder has one eccentric port, flat piston and flat cylinder-head. The comparisons with experimental data show fairly well qualitative agreement.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1995년도 추계학술대회논문집
• /
• pp.69-75
• /
• 1995

The deformation behavior of stainless steel-clad aluminum sheet metals under uniaxial tension has been investigated. The differences in mechanical properties such as elastic modulus, flow stress and plastic strain ratio, of component layers of the composite sheet gave rise to warping of the tensile specimens. The warping has been analyzed by FEM and the total force and momentum equilibria. The analyzed radii of curvature of the warped specimens were smaller than the measured data possibly due to elastic recovery during unloading. The differences in mechanical properties may also give rise to transverse stresses in the component layers. The transverse stresses have been analyzed on the assumption of isostrain and by the FEM in which the warping has been taken into account. The transverse stresses calculated by the FEM were lower than those by the isostrain hypothesis due to stress relaxation by the warping and turned out to be negligible compared with the longitudinal stresses. Consequently, the flow stresses of the composite sheets follow the rule of mixtures.

• Journal of Mechanical Science and Technology
• /
• 제14권7호
• /
• pp.789-795
• /
• 2000

Free-surface flows with an arbitrary deformation, induced by a submerged hydrofoil, are simulated numerically, considering two-fluid flows of both water and air. The computation is performed by a finite volume method using unstructured meshes and an interface capturing scheme to determine the shape of the free surface. The method uses control volumes with an arbitrary number of faces and allows cell wise local mesh refinement. The integration in space is of second order, based on midpoint rule integration and linear interpolation. The method is fully implicit and uses quadratic interpolation in time through three time levels. The linear equations are solved by conjugate gradient type solvers, and the non-linearity of equations is accounted for through Picard iterations. The solution method is of pressure-correction type and solves sequentially the linearized momentum equations, the continuity equation, the conservation equation of one species, and the equations for two turbulence quantities. Finally, a comparison is quantitatively made at the same speed between the computation and experiment in which the grid sensitivity is numerically checked.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2007년도 동계학술발표대회 논문집
• /
• pp.534-539
• /
• 2007

The objectives of the present work is to investigate the influence of the solution cooled absorber(SCA), refrigerant drain heat exchanger(RSX), exhaust gas/solution heat exchanger(ESX) and high efficiency solution heat exchanger on COP for a double-effect series-flow absorption chiller. A simulation program has been prepared for the cycle analysis of absorption chillers. As a result, Solution heat exchangers(LSX, HSX) are a most effective element for the COP than the others. In spite of the poor contribution to COP, SCA make a rule to reduce the crystallization phenomena of LiBr solution at solution heat exchanger. And the optimum solution split ratio are varied with the relative size of RSX and LSX.

• Structural Engineering and Mechanics
• /
• 제4권1호
• /
• pp.9-23
• /
• 1996

The behaviour of elasto-plastic planar arches subjected to dynamic loads in presented. The governing equations are formulated through the dynamic equations and compatibility conditions. The latter is established by applying the generalized conjugate segment analogy. Bending moments at the nodes and axial forces in the members are considered as primary variables in the elastic regime. They are supplemented by the rotations at the nodes and dislocations in the elements when plastic hinges occur. Newmark-${\beta}$ method is adopted in the time marching process. The interaction diagram of each element is treated as the yield surface for the element and the associated flow rule is enforced as plastic flow occurs. The method provides good prediction of dynamic response of elasto-plastic arches while requiring small core storage and short computer time.

• 산업경영시스템학회지
• /
• 제18권36호
• /
• pp.105-112
• /
• 1995

This paper presents that model 1 is to show an approach to determining unidirection or bidirection of the optimal flow path design, model 2 is to show the design of an AGV can determine the minimum number of required vehicles. Our purposes of this article are that first, it is easy to see that computationlly advanced efficient procedure with some pairwises of comparision, zero-one integer and northwest rule by using, second, to determine the minimum number of vehicles in the layout for manufacturing facility, we used a coefficient ratio with moved numbers of loaded & unloaded vehicles between stations and available time of AGV's capacity for per shift per vehicle. Example is presented to demonstrate the approach.

• 한국농공학회지
• /
• 제44권2호
• /
• pp.127-135
• /
• 2002

Due to the fact that the design of a reinforced concrete structure changes in accordance with its shape and assigned load, total automation of the design system has not been achieved. For instance, since there is no general rule about setting up reinforcing steel quantity and arrangement location, it is simply not feasible to automatically decide the reinforcing arrangement location. In this study, the ESO(evolutionary structural optimization) technique and its related issues will be discussed. The ESO techniques is determined the reasonable load path which is traveling of load between in-flow and out-flow at a concrete structure using numerical analysis. And the results applied to the steel arrangement in reinforced concrete structures. The optimal algorithm, which determines the terminal criteria during ESO process, has been updated by using the obtained results. And the load path within the member has been determined automatically.