• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.06a
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• pp.51-62
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• 2004

• Journal of Korea Foundry Society
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• v.43 no.3
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• pp.175-181
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• 2023

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.146-151
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• 2007

Resistant starch (RS) content, paste viscosity, water solubility and absorption index, bulk density, color, compression force, and bowl life of Goami flakes manufactured by extrusion process were determined to evaluate Goami (high fiber rice) as a food material. Various extrusion process conditions included barrel temperature (90, 110, $130^{\circ}C$) and moisture content (50, 55%). RS content in the extruded pellet and defatted flake ranged from $8.00{\sim}8.56%$ and $6.57{\sim}9.53%$ respectively. RS content increased as moisture increased from 50% to 55%. Peak viscosity, trough viscosity, final viscosity, and setback viscosity of the extruded pellet and defatted flake decreased with steeping for 1 hr, and the breakdown viscosity significantly increased. The water solubility and absorption index increased in the flake compared to Goami and extruded pellet. The water solubility index of the extruded pellet was lower than that of Goami, while its water absorption index was higher than Goami. The bulk density of the flake ranged from $0.35{\sim}0.44$ g/mL. The bowl life of the flake was $12.4{\sim}19.4$ min, which was longer than commercial breakfast cereals on the market.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1585-1593
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• 2015

3D-structured (embossed) aluminum sheets have been used in the heat insulation purpose for automative exhaust parts because of increasing their surface areas and stiffness reinforcement imposed in making the embossing pattern. However, there are many restrictions in press forming of the embossed sheet compared with the flat sheet (non-embossed one) because of its difference in the mechanical properties and the geometrical 3-dimensional shape. In this paper we investigated the deformation characteristic of embossed aluminum sheet in the incremental sheet forming process which has frequently used in the design verification and the trial manufacturing of sheet products. The single point incremental forming (SPIF) experiments for the rectangular cone forming using the CNC machine with a chemical wood-machined die and a circular tool shape showed that the formability of the embossed sheet are better than that of the flat sheet in view of the maximum angle of cone forming. This comes from the fact that the embossed sheet between the tool and the elastic die wall is plastically compressed and the flatted area contributes to increase the plastic deformation. Also the tool path along the outward movement from the center showed a better formability than that of the inward movement from the edge. However the surface quality for the tool path along the outward movement evaluated from the surface deflection is inferior than that of the tool path along the inward movement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.219-226
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• 2010

The stamping process is widely used in fabricating various sheet-parts for vehicle, airplane, and electronic devices due to its low processing cost and high productivity. Recently the use of thin sheets with corrugated structures has rapidly increased for the production of energy devices, e.g., heat exchangers and fuel cells. However, it is very difficult to make corrugated structures directly in the stamping process due to their geometrical complexity. To solve this problem, this paper proposes a multi-step stamping process with a combined heat treatment process: a sequence of the first stamping, heat treatment, and second stamping. By multi-stamping, we obtained successful results in fabricating very thin corrugated structures with thicknesses of $100{\mu}m$; these are applicable as part of a plate-type heat exchanger.

• Journal of the Korean Magnetics Society
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• v.5 no.6
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• pp.937-946
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• 1995

In this research, the processing control of NiCuZn Ferrite has been developed. The relationship between initial permeability and bulk density of NiCuZn Ferrite with processing factors was studied. NiCuZn Ferrite, which calcinated at $700^{\circ}C$ for 3 hours, was ball milled for about 60 hours to make a size of $0.5\mu\textrm{m}$ followed by granulation using spray dryer. The physical properties and the magnetic properties of NiCuZn Ferrite were investigated with the processing factor, such as (i) granule size and forming pressure, and (ii) sintering temperature. The green density of NiCuZn Ferrite was largely depended on the forming pressure rather than its granule size. The green density of NiCuZn Ferrite was increased from $2.484\;g/cm^{3}$ to $3.002\;g/cm^{3}$ with increase in forming pressure. The bulk density of NiCuZn Ferrite was increased from $3.470\;g/cm^{3}$ to $4.754\;g/cm^{3}$ linearly with increase in sintering temperature. The relationship between initial permeability and bulk density of NiCuZn Ferrite was expressed with the empirical equation,$\mu_{i}=a+b_{\rho}+c_{\rho}^2$ at forming pressure and sintering temperature.

• Journal of Korea Foundry Society
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• v.27 no.5
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• pp.212-216
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• 2007

과공정 Al-15wt.%Si 합금의 주단조 공정의 적용을 위해 주조 예비성형체를 제작하는 과정에서 P와 Sr을 첨가하여 과공정 Al-Si 합금의 응고과정에서 발생하는 초정 Si과 공정 Si의 미세화 개량처리를 행하였다. 미세화 조직의 변화에 따른 기계적성질 및 단조성을 조사하였으며, 미세화제로 첨가된 0.075wt.% Sr과 0.1wt.% P의 첨가에서 가장 효과적인 미세한 조직을 얻을 수 있었고, 인장강도와 연신율은 이들 첨가원가의 증가에 따라 향상되는 결과를 보였으나 일정 이상의 첨가에서는 더 이상의 향상은 없었다. 단조성 평가를 위한 열간가공 재현실험에서는 $450^{\circ}C$에서 약60N/mm2의 하중이 필요함을 알 수 있었다. 열간단조 및 열처리 후의 인장강도와 연신율은 보다 많은 향상을 가져왔으며, 이는 압축가공에 의한 주조 예비성형체 내부에 잔존하던 주조결함의 제어와 열처리에 의한 조직의 개량 및 균질화 효과에 의한 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.672-678
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• 2020

Ogive parts of large-caliber ammunition in Korea are manufactured by the Press Nosing method, but this method has the disadvantage of requiring additional processes such as lubrication before and after the press process. This study proposes the possibility of applying the Swaging method to improve these shortcomings. A large-diameter shell body was manufactured in sub-scale and plastic working experiments using a swaging process were performed. We investigated whether plastic processing is possible up to 75 % of the diameter reduction rate that satisfies the final molding dimension, and whether the dimensions of the product produced by swaging molding are satisfactory as the hardness changes according to the diameter reduction rate and the increase in thickness. The test using the prototype confirmed that the hardness increased proportionally with the diameter reduction rate and by more than HV 335 at the reduction rate of 75 %. The material thickness variation tended to be similar to the theoretical calculated value, and the thickness increase rate was proportional to 65.4 % at the reduction rate of 75 %.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.4
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• pp.375-382
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• 2015

The dome and neck part of a vessel is generally formed by a hot spinning process with a seamless tube. However, as studies on and design data from the hot spinning process are insufficient, this process has been performed based on trial and error and the experiences of field engineers. Changes in the inner diameter from the bottom to the top of the neck have occurred mainly because of the characteristics of the hot spinning process due to the high-speed rotation of the rollers. In this study, a theoretical and finite element analysis of the vessel is conducted with different material(Cr-13)-supplemented screw threads for tapping and to reduce shape errors. Based on the results, tne structural safety under the operating conditions is evaluated.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.12
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• pp.635-640
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• 2016

It is important factors for a production system to get a profitable result in quality and reliability process. For this reason, there's are various type of research papers in a certain type of data acquisition and application to reliability and quality of the level of M2M devices. In general, a classification problem of slightly different signal such as sensing data is difficult to do with classical statistical methods. There's required real-time and instantaneous calculation properties in machine process. Especially a type of injection molding machine which has a property to be decided in accordance with short-term cycle process needs a solution that can be done a certain type of decision like as good or bad quality immediately. This paper presents a simple application of Kalman Filtering by single sensing data to injection molding process in order to get a correct answer from the real time sensing data.