• Transactions of Materials Processing
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• v.6 no.4
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• pp.311-318
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• 1997

In recent years, compression molding of fiber-reinforced thermoplastics has been increased in commercial aspects. During a compression molding process of composites, the flow analysis must be developed in order to accurately predict the finished part properties as a function of the molding process parameters. In this paper, a new model is presented which can be used to predict the flow under consideration of the slip of mold-composites and extensional & shear viscosity ratio M and slip parameter$\alpha$ on the mold filling parameters are discussed.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.755-756
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• 2006

This paper presents the temperature distribution of the oil-immersed self-cooled transformer with radiator performed by coupled magneto-fluid-thermal analysis. Particularly, 3D temperature distribution of cooling oil and sub-components under the natural convection is obtained by computational fluid dynamics analysis, while heat sources are predetermined by magnetic field analysis using F.E.M. The predicted temperature distribution of the power transformer model is compared with the measured data for verifying the validity of the proposed analysis.

• Lingua Humanitatis
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• v.5
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• pp.221-264
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• 2003

This paper takes issue with the idea of language as a 'serial-time structure' as opposed to the 'real-time event' of speech, an idea entrenched in Chomskyan model of linguistic theory. The discussion centers around the leitmotif question: Is language constructed entirely from a finite set of apriori discrete symbol types, as the 'competence vs performance' dichotomy implies\ulcorner A set of linguistic patterns examined in this study, largely with regard to phonological considerations, points to the evidence to the contrary. That is, while the patterns may be said to be linguistically distinct, they are not discretely, different, i.e. not different enough to be reliably differentiated. It is demonstrated that much of current research in phonology, including the most recent Optimality Theory, is misdirected in that it falsely presupposes a discrete universal phonetic inventory. The main thrust of the present study is that there is no sharp boundary between 'competence' defined as the formal, symbolic, discrete time domain of language and human cognition on the one hand and 'performance' as the continuous, fuzzy, real-time domain of human physiology on the other.

• Structural Engineering and Mechanics
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• v.37 no.2
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• pp.163-175
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• 2011

The results of experimental and numerical investigations on reinforced concrete beams, with different longitudinal rebars affected by corrosive processes are presented in this paper. Different diameters and/or different distributions of longitudinal rebars were employed keeping constant the total section in each analyzed case, (maintaining a constant stirrup diameter and distribution). The rebars were subjected to accelerated corrosion in the experimental study. Electrochemical monitoring of the process, periodic measuring of the cover cracking and gravimetry of the rebars were performed through the test. Some building recommendations are obtained in order to be considered by designers of concrete structures. The numerical simulation was carried out through the application of the Finite Element Method (FEM), employing plane models, and using linear-elastic material model. The cracking process was associated with the evolution of the tensile stresses that were originated. This numerical methodology allows the monitoring of the mechanical behavior until the beginning of the cracking.

• Selected Papers of The Society of Naval Architects of Korea
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• v.1 no.1
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• pp.91-100
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• 1993

A displacement-based finite element method Is presented for the geometrically nonlinear analysis of eccentrically stiffened plates. A nonlinear degenerated shell element and a nonlinear degenerated eccentric isoparametric beam (isobeam) element are formulated on the basis of Total Agrangian and Updated Lagrangian descriptions. In the formulation of the isobeam element, some additional local decrees of freedom are implementd to describe the stiffener's local plate buckling modes. Therefore this element can be effectively employed to model the eccentric stiffener with fewer D.O.F's than the case of a degenerated shell element. Some detailed buckling and nonlinear analyses of an eccentrically stiffened plate are performed to estimate the critical buckling loads and the post buckling behaviors including the local plate buckling of the stiffeners discretized with the degenerated shell elements and the isobeam elements. The critical buckling loads are found to be higher than the analytical plate buckling load but lower than Euler buckling load of the corresponding column, i.e, buckling strength requirements of the Classification Societies for the stiffened plates.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.E
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• pp.364-372
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• 1993

The purpose of this study is to analyze traffic patterns by use of TRANSYT-7F Model, and to choose the optimum traffic-light cycle length and cycle splite to improve traffic flow and air quality at Samsung Intersection in Seoul. Emission rates of air pollutants are calculated for three time segments 0700-0900, 0900-1800 and 1800-2000. The traffic volume correlated reasonably well with air pollutants emitted ; however, the phasing and timing of traffic signals was found to equally be important. The results of performance with optimal setting indicate that the best cycle length were 80sec(0700-0900), 95sec(0900-1800) and 90sec(1800-2000), res-pectively. As expected the highest emissions of air pollutants were observed during the evening rush hours (1800-2000). A properly designed signalized intersection can help reduce traffic delay, driver discomfort, fuel consumption, and air pollution by efficiently the capacity of existing intersection.

• Structural Engineering and Mechanics
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• v.12 no.3
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• pp.231-248
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• 2001

The three-dimensional behavior of confined concrete was investigated, including strength enhancement due to triaxial compressive stresses, lateral expansion, compression softening, cover spalling and post-peak ductility. A finite element program based on a nonlinear elasticity methodology was employed to evaluate the ability to model triaxial behavior of reinforced concrete (RC) by combining constitutive models proposed by several researchers. The capability of compression field based models to reproduce the softening behavior of lightly cracked confined concrete was also investigated. Data from tested specimens were used to evaluate the validity of the formulations. Good agreement with the experimental results was obtained.

• Computers and Concrete
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• v.2 no.6
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• pp.455-479
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• 2005

This paper describes a 2D nonlinear finite element analysis (NLFEA) platform that combines heat flow analysis with realistic analysis of cracked reinforced concrete structures. The behavior models included in the structural analysis are mainly based on the Modified Compression Field Theory and the Distributed Stress Field Model. The heat flow analysis takes into account time-varying thermal loads and temperature-dependent material properties. The capability of 2D nonlinear transient thermal analysis is then implemented into a nonlinear finite element analysis program VecTor2(C) for 2D reinforced concrete membranes. Analyses of four numerical examples are performed using VecTor2, and results obtained indicate that the suggested nonlinear finite element analysis procedure is capable of modeling the complete response of a concrete structure to thermal and mechanical loads.

• Structural Engineering and Mechanics
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• v.17 no.5
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• pp.727-734
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• 2004

An uncoupled computational model for analyzing the hygrothermal dynamic response of composite laminates has been developed. The constitutive equations, expressed in an integral form, and involving relaxation moduli are adopted, to describe the non-aging hygrothermorheologically simple materials. A Prony series represents the relaxation moduli is exploited in order to derive a recursive relationship, and thereby eliminate the storage problem that arises when dealing with material possessing memory. The problem is formulated in a descritized variational form. Mindlin and higher order finite elements are employed for spatial descretization, while the Newmark average acceleration scheme is exploited for temporal descritization. The adopted recursive formula uses only the details of the previous event to compute the details of the current one. Numerical results of the displacement fields of both thin and thick viscoelastic laminates problems are discussed to show up the effectiveness of Mindlin and higher-order shear theories.

• Journal of Magnetics
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• v.4 no.3
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• pp.84-87
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• 1999

It is shown that progressive crystallization of non-magnetostrictive Co-based metallic glass (VITROVAC 6030) leads to an increase of coercivity by more than three orders of magnitude. The mechani는 responsible for this phenomenon are interpreted showing that the main source for the giant increase of the coercivity is the pinning effect on the domain walls originating from the created crystallites of the size much smaller than the domain width (correlation length for ferromagnetic exchange interactions). It is also shown that gradually devitrified non-magnetostrictive metallic glass is an excellent model material for verification of N el's theory describing the Rayleigh rule.