• Korean Journal of Materials Research
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• v.16 no.11
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• pp.668-675
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• 2006

In the partial squeeze casting process, the filling behavior of liquid metal and solidification pattern in thick area have significant influence on the quality of casting products and die life. For the optimal casting design of automobile transmission gear housing, various analyses were performed in this study by using computer simulation code, MAGMAsoft and the simulation results were compared and analyzed with experimental results. By air pressure criteria, internal porosities caused by air entrap during the mold filling were predicted and reduced remarkably by modification of gating system. Also, optimal squeeze-time lag to apply partial squeeze pin in thick area was calculated and the castings was free from shrinkage defects with the result of solidification analysis. Consequently, casting design for automobile transmission gear housing was optimized and approved by Computer Tomography.

• Design & Manufacturing
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• v.11 no.1
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• pp.14-18
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• 2017

Recently, the injection-molded products are lighter, and thinner than ever. In this work, Injection molding simulation was conducted to analysis the filling pattern imbalance in high speed injection molding process for thin-wall injection component, 8 inches LGP. Numerical analysis shows that shear heated polymer near the side wall causes filling imbalance between center and side of cavity. Short shot experiments were conducted and compared with simulation results. Filling imbalance ratio showed a tendency to increase for wider fan gate.

• Journal of Korea Foundry Society
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• v.18 no.6
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• pp.578-585
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• 1998

A multi-purpose code MAGMA was employed for mold design and process control in producing Al wheel by lowpressure die casting. Three-dimensional solid modeling was followed by mesh generation of casting and molds(top, bottom and side). The simulation of stability of casting cycle time, mold filling simulation with pressure variation from P1 to P2, solidification simulation by solidification time and feeding criteria, and temperature distribution of molds during processes were studied in this research. The thermal stability of molds was attained after 5 cycles when molds were preheated at $400^{\circ}C$. The pressure increase from P1 to P2 for mold filling was evaluated as slightly higher, and 6 seconds were taken for the mold filling. The cycle time was believed to be designed properly judged from the solidification time of casting and open/close time of molds.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4C
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• pp.232-240
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• 2011

While the water-filling algorithm is an efficient power allocation method that maximizes the ergodic capacity of adaptive MIMO systems, its excessive residual power causes spectrum loss in real systems employing discrete modulation indices. In this paper we propose new power allocation algorithms that improve the spectral efficiency of MIMO systems by efficiently reallocating the residual power of the water-filling algorithm. We apply the proposed algorithms to the adaptive turbo-coded MIMO system to verify their performance through computer simulation in various environments. Simulation results show that the spectral efficiency of the proposed algorithms is better than that of the water-filling algorithm by about 8.9% at SNR of 20dB in Rayleigh fading environments.

• Korea-Australia Rheology Journal
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• v.21 no.1
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• pp.71-79
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• 2009

The incomplete saturation and the void formation during the resin infiltration into fibrous porous media in the resin transfer molding process cause failure in the final product during its service. In order to better understand flow behavior during the filling process, a finite-element scheme for transient flow simulation across the micro-structured fibrous media is developed in the present work. A volume-of- fluid (VOF) method has been incorporated in the Eulerian frame to capture the evolution of flow front and the vertical periodic boundary condition has been combined to avoid unwanted wall effect. In the microscale simulation, we investigated the transient filling process in various fiber structures and discussed the mechanism leading to the flow fingering in the case of random fiber distribution. Effects of the filling pressure, the shear-thinning behavior of fluid and the volume fraction on the flow front have been investigated for both intra-tow and the inter-tow flows in dual-scale fiber tow models.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.477-480
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• 1995

Dccisions of optimal filling conditions for the chip encapsulation have been done primarily by an ad hoc use of expertise accumulated over the years because the chip encapsulation process is quite complicated. The current CAE systems do not provide mold designers with necessary knowledge of the chip encapsulation for the successful design of optimal filling except flow simulation capability. There have been no attempts to solve the optimal filling problem in the process of the chip encapsulation. In this paper, we have constructed an design system for optimal filling to avoid short shot in the chip encapsulation process which combines an optimization methodology with CAE software.

• Structural Engineering and Mechanics
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• v.81 no.2
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• pp.243-258
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• 2022

In this paper, tensile behavior of joint filling has been investigated under experimental test and numerical simulation (particle flow code). Two concrete slabs containing semi cylinder hole were prepared. These slabs were attached to each other by glue and one cubic specimen with dimension of 19 cm×15 cm×6 cm was prepared. This sample placed in the universal testing machine where the direct tensile stress can be applied to this specimen by implementing a special type of load transferring device which converts the applied compressive load to that of the tensile during the test. In the present work, two different joint filling thickness i.e., 3 mm and 6 mm were prepared and tested in the laboratory to measure their direct tensile strengths. Concurrent with experimental test, numerical simulation was performed to investigate the effect of hole diameter, length of edge notch, filling thickness and filling length on the tensile behavior of joint filling. Model dimension was 19 cm×15 cm. hole diameter was change in four different values of 2.5 cm, 5 cm, 7.5 cm and 10 cm. glue lengths were different based on the hole diameter, i.e., 12.5 cm for hole diameter of 2.5 cm, 10 cm for hole diameter of 5 cm, 7.5 cm for hole diameter of 7.5 cm and 5 cm for hole diameter of 10 cm. length of edge notch were changed in three different value i.e., 10%, 30% and 50% of glue length. Filling thickness were changed in three different value of 3 mm, 6 mm and 9 mm. Tensile strengths of glue and concrete were 2.37 MPa and 6.4 MPa, respectively. The load was applied at a constant rate of 1 kg/s. Results shows that hole diameter, length of edge notch, filling thickness and filling length have important effect on the tensile behavior of joint filling. In fixed glue thinks and fixed joint length, the tensile strength was decreased by increasing the hole diameter. Comparing the results showed that the strength, failure mechanism and fracture patterns obtained numerically and experimentally were similar for both cases.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.3-7
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• 2002

The die casting process was used to manufacture a alternator housing for automobile. Specially automobile parts were required light and hight strength. Therefore simulation have been carried out die casting process of the alternator housing. In this paper, we investigated about characteristics of the die casted alternator housing the HPDC(High Pressure Die Casting) process. Also we designed the die casting die with the simulation results of the alternator housing. The MAGMAsoft and Auto-CAD was used as computer simulation and design code and used material was ADC12(Aluminum Die Casting Alloy). We present the results of filling behavior and design of die process of the alternator housing cast. The result obtained about filling behavior and design of die of the cast showed good agreement with test result.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.5
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• pp.85-90
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• 2011

In this paper a design procedure via computer-aided molding simulation is presented to optimize the air-trap locations in a speaker encloser of mobile phone. The molding flow simulation reveals that the race-tracking phenomenon is the dominant feature in the current mold design. In obtaining an optimal filling pattern, the local modifications of the wall thickness such as in a flow leader attachment are considered as the primary control factor, and both the gate position and the filling time become the secondary control factor. In the one-at-a-time approach, the last location to be filled in the mold cavity could be successfully moved to the extremities of the part, allowing a natural ventilation of entrapped air through the mold parting plane.

• Transactions of Materials Processing
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• v.9 no.4
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• pp.413-420
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• 2000

In the die casting process, the flow of liquid metal has significant influence on the quality of casting products and die life. For the optimal process design of front housing part of aircon compressor, various analyses were performed in this study by using computer simulation code, MAGMAsoft. The simulation has been focused on the molten metal behaviors during the filling and solidification stages for the sound casting products. Two cases of casting design that have different types of gating system are considered in the analysis. The potential sites where the casting defects may occur is examined by computer simulation and an improved design process is proposed. Also the effect of partial squeeze on the quality of casting products is considered and the optimal time lag after filling process is determined. For the die-stability, the effect of operational parameters such as die temperature, heat cycle and spot cooling on the die life has also been analyzed.