• Design & Manufacturing
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• v.9 no.2
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• pp.34-37
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• 2015

The HEV Traction Motor Core manufacturing technology is a core component of HEV Traction Motor Core (Iron Core) is a key technology for the manufacture of eco-friendly automotive industry is essential for the competitiveness of the country must obtain the technology. In this study, the HEV Motor Core of the Rotor manufacturing technology, the Stator manufacturing technology applied to Press Lamination Die and Core(Iron Core) was developed and the results are discussed.

• Design & Manufacturing
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• v.8 no.2
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• pp.7-11
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• 2014

The Core-Shift is often generated on injection mold which have thin and long core. And Core-Shift brings out problems for thickness variation and product ejecting process. In this study, analysis of Core-Shift was performed according to change of materials of core(steel P-20, Be-Cu) and various polymers(PP, PC) by using MoldFolw MPI 6.1 which is commercial injection molding analysis program. As the results of analysis, the magnitude of Core-Shift was increased as being use polymer had lower fluidity and lower rigidity core. In the future, we will study the relationship between amount of Core-Shift and ejecting force.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1184-1186
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• 2009

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.2107-2110
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• 2009

• Bulletin of the Korean Chemical Society
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• v.29 no.11
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• pp.2247-2251
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• 2008

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.6
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• pp.682-697
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• 2001

This investigation evaluated the fracture toughness($K_{IC}$) of eight currently available core materials, and relate the fracture toughness value to fractography analysis and surface characteristics using a atomic force microscope (AFM). Single-edge notched (SEN) test specimens (n=10) and compact tension (CT) test specimens (n=10) were prepared conforming to the ASTM Standard E-399 for a high copper amalgam, three composite core materials (Core-Max II, Core Paste, Bisfil Core), two reinforced composite core materials (Ti-Core, Ti-Core Natural), a resin-modified glass ionomer core material (Vitremer), and a conventional glass ionomer core material (Ketac-Molar). The specimens were tested with an Instron Universal Testing Machine. The maximum loads were measured to calculate the fracture toughness ($K_{IC}$). Thereafter, fracture surfaces of SEN specimens of each material were investigated for fractography analysis using scanning electron microscope. And, disc-shaped specimens with 1mm thickness were fabricated for each material and were investigated under AFM for surface morphology analysis. The results were as follows: 1. Bisfil Core showed the highest mean fracture toughness regardless of test methods. 2. For the tooth-colored materials, Ti-Core Natural exhibited the highest fracture toughness. 3. Ketac Molar showed a significantly low fracture toughness when compared with the amalgam and the composite resin core materials(p<0.05). 4. The fracture toughness values obtained with the single-edge notched test, except Ketac Molar, were higher than those obtained in the compact tension test. 5. SEM revealed that the fracture surface of high fracture toughness material was rougher than that of low fracture toughness material. 6. AFM revealed that the surface particles of the composite resins were smaller in size, with a lower surface roughness than the glass ionomer core materials.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.4
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• pp.1-10
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• 2009

This study has intended to build ecological networks in consideration of life-zones inside Cheongju city through biotope grade, GIS network analysis etc. This study consisted of following three steps. First, we selected core districts and core spot districts using land use patten and biotope grade. The core district included the first grade of biotope and forest land. The core district consisted of two sectors : east axis core, Uam mountain; west axis core, Bumo mountain. The core spot district included the first grade of biotope. The core spot districts consisted of two sectors : north axis base core, Myongshim park; south axis base core, Guryong park. Second, the base district included the second grade of biotope and park and school. We used buffering analysis within 500m of the base district and selected the new base district. Third, we connected core districts and base core districts using least cost analysis of GIS. Thus we built comprehensive ecological networks in consideration of life-zones through GIS.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.1061-1063
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• 2010

• Design & Manufacturing
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• v.9 no.1
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• pp.9-13
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• 2015

The HEV/EV Traction Motor Core manufacturing technology is a core component of Traction Motor Core is a key technology for the manufacture of eco-friendly automotive industry is essential for the competitiveness of the country must obtain the technology. This study was performed to develop a Rotor Core of the HEV/EV Traction Motor using the first time in Korea multi-gate BMC injection molding technique. Executed by the experiment of this study are as follows. Study 1: Developed a multi-gate BMC injection mold for the magnet fixed to the Rotor Core. Study 2: Developed a production implementation and manufacturing technology of the Rotor Core. In this study, the develop products and manufacturing technologies implemented by the BMC injection mold development for Magnet fixed to the Rotor Core and the results are discussed.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.134-140
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• 2017

A well-performed core power control to track load changes is crucial in pressurized water reactor (PWR) nuclear power stations. It is challenging to keep the core power stable at the desired value within acceptable error bands for the safety demands of the PWR due to the sensitivity of nuclear reactors. In this paper, a state-space model predictive control (MPC) method was applied to the control of the core power. The model for core power control was based on mathematical models of the reactor core, the MPC model, and quadratic programming (QP). The mathematical models of the reactor core were based on neutron dynamic models, thermal hydraulic models, and reactivity models. The MPC model was presented in state-space model form, and QP was introduced for optimization solution under system constraints. Simulations of the proposed state-space MPC control system in PWR were designed for control performance analysis, and the simulation results manifest the effectiveness and the good performance of the proposed control method for core power control.