• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.349-352
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• 2006

The conventional segregated finite element formulation produces a small and simple matrix at each step than in an integrated formulation. And the memory and cost requirements of computations are significantly reduced because the pressure equation for the mass conservation of the Navier-Stokes equations is constructed only once if the mesh is fixed. However, segregated finite element formulation solves Poisson equation of elliptic type so that it always needs a pressure boundary condition along a boundary even when physical information on pressure is not provided. On the other hand, the conventional integrated finite element formulation in which the governing equations are simultaneously treated has an advantage over a segregated formulation in the sense that it can give a more robust convergence behavior because all variables are implicitly combined. Further it needs a very small number of iterations to achieve convergence. However, the saddle-paint-type matrix (SPTM) in the integrated formulation is assembled and preconditioned every time step, so that it needs a large memory and computing time. Therefore, we newly proposed the P2PI semi-segregation formulation. In order to utilize the fact that the pressure equation is assembled and preconditioned only once in the segregated finite element formulation, a fixed symmetric SPTM has been obtained for the continuity constraint of the present semi-segregation finite element formulation. The momentum equation in the semi-segregation finite element formulation will be separated from the continuity equation so that the saddle-point-type matrix is assembled and preconditioned only once during the whole computation as long as the mesh does not change. For a comparison of the CPU time, accuracy and condition number between the two methods, they have been applied to the well-known benchmark problem. It is shown that the newly proposed semi-segregation finite element formulation performs better than the conventional integrated finite element formulation in terms of the computation time.

• 한국경영과학회지
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• 제19권2호
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• pp.217-228
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• 1994

This paper presents a new integer formulation (Type III ALB) for a single model assembly line balancing problem. The objective of the formulation is to minimize the total idle time, which is defined as the product of the number of work stations and the cycle times minus the total work content. This formulation considers currently existing Type I (minimizing the number of work stations for a given cycle time) and type II (minimizing the cycle time for a given number of work stations) formulations as its special cases and provides the global minimum solutions of the cycle time and the number of work stations. This information would be of great value to line designers involved in designing new assembly lines and rebalancing old lines under flexible conditions. Solution methods based on combination of Type I and Type II approaches are also suggested and compared.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.17-18
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• 2022

Carbon dioxide emissions in the construction sector account for 38% of all industries, and environmental destruction is occurring due to indiscriminate use of natural resources. The purpose of this study is to develop by-product aggregate Non-Sintered Cement(NSC) that can replace sand used as natural aggregate and Portland cement. Therefore, Ground Granulated Blast Furnace Slag, Type C Fly Ash and Type F Fly Ash are used to replace cement, and water granulated ferro-nickel slag(FNS) is used to replace aggregate. The flow, compressive strength and flexural strength of the formulation using sand as an aggregate and the formulation replacing 100% FNS were compared. As a result of the experiment, the formulation using FNS had higher overall strength than the formulation using sand, and as the substitution rate of Type C fly ash increased, the strength was the best. Formulation using FNS is more fluid than using sand. Through this study, we show the possibility of 100% substitution of FNS and its applicability to secondary concrete products of by-product aggregate NSC.

• 한국환경농학회지
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• 제15권1호
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• pp.105-115
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• 1996

In this paper, we reviewed the degradation factors of diazinon which was known to be easily degraded by soil microorganisms and lost of its activity. Under submerged soil condition, the contribution of microorganisms to diazinon degradation was about 40% and these microorganisms preferred soil humus as substrates to diazinon itself. The effect of monooxygenase activity in submerged soil was more important than esterase activity on diazinon degradation and these enzymes were inhibited by several chemicals such as piperonyl butoxide(PBO), EPN and tricyclazole. From these results, new formulation type of diazinon (PBO and triphenyl phosphate were added to commercial diazinon formulation by 0.1% respectively.) and diazinon mixture formulation (diazinon was mixed with EPN, tricyclazole and carbofuran in equal amount) were prepared. The new formulation type of diazinon showed better insecticidal activity by 12% and more delayed diazinon degradation in ten days than commercial diazinon.

• 대한기계학회논문집B
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• 제33권4호
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• pp.242-247
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• 2009

AILU type preconditioners for a two-dimensional combined P2P1 finite element formulation of the interaction of rigid cylinder with incompressible fluid flow have been devised and tested by solving fluid-structure interaction (FSI) problems. The FSI code simulating the interaction of a rigid cylinder with an unsteady flow is based on P2P1 mixed finite element formulation coupled with combined formulation. Four different preconditioners were devised for the two-dimensional combined P2P1 finite element formulation extending the idea of Nam et al., which was proposed for the preconditioning of a P2P1 mixed finite element formulation of the incompressible Navier-Stokes equations. It was found that PC-III or PC-IV among them perform well with respect to computational memory and convergence rate for some bench-mark problems.

• 한국식품과학회지
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• 제25권5호
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• pp.481-486
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• 1993

본 연구는 유화형 소시지 제조시 전보에서 분석된 원료육의 성분과 기능성 자료를 데이타베이스로 하여, 컴퓨터를 이용한 최소가격배합을 자성하여 그 적용의 실례를 들고 제한조건의 하나로 설정된, 결착지수의 부합도를 실제 제품제조를 통해 검토한 후 적정 결착지수 제한조건을 찾기 위하여 실시하였다. 결착지수 제한조건을 달리하여 최소가격배합비로 제조한 프랑크푸르터소시지의 실측 결착성을 측정한 결과 예측치와 일치하지는 않았으나 비례하여 나타났으며, 일치하지 않은 이유는 결착지수가 모형시스템에 의해서 구해진 관계로 실제 제조공정과 조건이 다른 것으로 사려된다. 또한 조직감 분석대상들을 결착지수와 비교했을 때 소시지의 조직감을 표현하는 바람직한 지표로서 cohesiveness와 함께 hardness를 동시에 고려할 필요가 있었다. 시중 제품의 결착성과 경도를 고려하여 볼 때 본 연구의 결착지수 제한조건은 $0.16{\sim}0.17$로 설정될 수 있었다.

• 펄프종이기술
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• 제46권3호
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• pp.73-80
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• 2014

In this study, in order to investigate the influence of insolubilizer on the double coating structure, we carried out basic research related to the double coating formulation with four insolubilizers having various chemical types such as amino aldehyde, glyoxal and two metallic salts. It was found that although the four insolubilizers showed similar results on optical and surface properties of the coated papers, they gave different results in the printabilities of the coated papers since coating structure was significantly influenced by different reacting mechanism of the insolubilizers. Three of the insolubilizers (glyoxal, two metallic salts) showed better results than amino aldehyde type one when they were applied to top coating formulation. Metallic salts type insolubilizers showed good results in the print gloss when it was applied to top coating formulation. It was believed that amino aldehyde type insolubilizer applied top coating formulation showed good both of dry-pick and wet-pick strength.

• Structural Engineering and Mechanics
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• 제7권2호
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• pp.203-216
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• 1999

A previously proposed finite element formulation method is refined and modified to generate a new type of elements. The method is based on selecting a set of general solution modes for element formulation. The constant strain modes and higher order modes are selected and the formulation method is designed to ensure that the element will pass the basic single element test, which in turn ensures the passage of the basic patch test. If the element is to pass the higher order patch test also, the element stiffness matrix is in general asymmetric. The element stiffness matrix depends only on a nodal displacement matrix and a nodal force matrix. A symmetric stiffness matrix can be obtained by either modifying the nodal displacement matrix or the nodal force matrix. It is shown that both modifications lead to the same new element, which is demonstrated through numerical examples to be more robust than an assumed stress hybrid element in plane stress application. The method of formulation can also be used to arrive at the conforming displacement and hybrid stress formulations. The convergence of the latter two is explained from the point of view of the proposed method.

• Smart Structures and Systems
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• 제13권4호
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• pp.517-546
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• 2014

This paper proposes a refined electro-mechanical beam formulation. Lagrange-type polynomials are used to interpolate the unknowns over the beam cross section. Three- (L3), four- (L4), and nine-point(L9) polynomials are considered which lead to linear, bi-linear, and quadratic displacement field approximations over the beam cross-section. Finite elements are obtained by employing the principle of virtual displacements in conjunction with the Carrera Unified Formulation (CUF). The finite element matrices and vectors are expressed in terms of fundamental nuclei whose forms do not depend on the assumptions made. Additional refined beam models are implemented by introducing further discretizations, over the beam cross-section. Some assessments from bibliography have been solved in order to validate the electro-mechanical formulation. The investigations conducted show that the present formulation is able to detect the electro-mechanical interaction.

• 한국수산과학회지
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• 제36권5호
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• pp.454-457
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• 2003

A feeding trial was carried out to investigate the utilization of dietary soybean meal and wheat flour as substitutes for fish meal and alginate in different dietary types (powder, pellet and flake) for juvenile snail (Semisulcospira gottschei). After 10 weeks feeding trial, survival was not affected by formulation and type of diets (P>0.05), but weight gain was significantly affected by dietary formulation (P<0.001) and type (P<0.05). In the same dietary formulation, weight gain of the snail fed the flake type of diets was lower than that of the snail fed the powder or pellet types. However, the type of diet did not affect weight gain when snail fed diets containing $37\%$ soybean meal and $18\%$ alginate. The weight gain was lower in the snail fed diets containing $25\%$ fish meal compared with that of the snail for diets containing $33-37\%$ soybean meal at the same dietary type. When soybean meal was used as main protein source in diets, weight gain was not affected by dietary alginate $(0\;and\;18\%)$ and wheat flour $(36\;and\;58\%)$ contents. Crude protein and ash contents of whole body of the snail was not affected either by formulation or by type of diet. Moisture and crude lipid contents of the whole body were significantly affected by dietary formulation, but not by the type. These results indicate that $25\%$ fish meal could be replaced by $37\%$ soybean meal as dietary protein source, and pellet and powder could be desirable dietary type for the optimum growth of the snail.