• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.10
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• pp.49-56
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• 1992

A new global routing algorithm which dynamically adjusts its cost parameters depending on the given routing poroblem to find a near optimum solution has been developed. The proposed algorithm efficiently performs global routing on general area in which all the pin positions are given. This algorithm is composed of two phases`In the first phase, it routes each net by searching a minimum cost path while ignoring the channel capacity. In the second iterative phase, it rips up nets which pass the channel at which the horizontal or vertical routing density exceeds the capacity and then it reroutes them using a modified set of cost parameters. Applying the above phases, paths for nets are found such that routing density doesn't exceed the capacity in each channel and that nets are routed with minimum cost. Experimental results for several benchmark examples including difficult-4, difficult-8, difficult-16, Primary1 and Primary2 show that our method generates better results than other published ones.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.118.1-118
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• 2001

In this paper, we suggest a new distribution model for a single phase transformer which is different from the existing model which was modeled for only primary parts, but new distribution model is modeled for primary and secondary parts. Using this model, we simulate various faults of the transformer to know how the transfer function vary from the normal one, i.e., the trend of the variation of transfer function. As an another approach, we measure the voltage and current of a three phase transformer while various faults are made at the transformer. From the simulation of the model and experiment, we fine some trends of the variation of transfer function.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.247-248
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• 2006

In this study, the morphology of the change of primary Al phase in A356 alloy by two kinds of electromagnetic stirrers(vertical and horizontal) were investigated to obtain the globular structure. The effects of the stirring current, the stirring time and the pouring temperature were determined. The greater stirring current and longer stirring time were to get the finer the Al phase. However, over a certain stirring current and stirring time, the primary Al was merged together and was increased. The reason is the degree of breakdown of initial dendrites has been decreased by the collision and coalescence of particles with increasing stirring current and stirring time. The optimum conditions and difference of the two kinds of electromagnetic stirrers have been investigated for rheology forming with controlled solid fraction.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.150-153
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• 2007

Apply electromagnetic stirring system to making rheology slurry of Al7075. This experiment has important element which is the relation between solid fraction percent and melt temperature of Al7075. The rheology slurry of Al7075 eliminated liquid phase to include alloying element of copper and zinc by squeeze casting process. In result the most structure was composed entirely of globular primary $\alpha$. Used this material for this study. This study made a comparison of mechanical property according to heat treatment T6 at each melt temperature ($619^{\circ}C$ and $615^{\circ}C$). The microstructure and component are observed how heat treatment T6 weight with the mechanical property by SEM-EDS.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1153-1163
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• 2005

Crown ether-based HPLC chiral stationary phases (CSPs) have been successfully utilized in the resolution of various racemic compounds containing a primary amino group. Especially, CSPs based on chiral crown ethers incorporating chiral binaphthyl unit or tartaric acid unit and based on phenolic pseudo chiral crown ethers have shown high chiral recognition efficiency. In this account paper, a review on the development of crown etherbased HPLC CSPs, their structural characteristics and applications to the resolution of racemic compounds including chiral drugs containing a primary or secondary amino group with the variation of the type and the content of mobile phase components and with the variation of the column temperature is presented.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.557-558
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• 2006

In all conventional sintered PM products, the pores present are of two types, primary and secondary. Primary pores forming during compaction and latter during sintering, due to penetration of formed liquid through the matrix grain boundary. Effect of carbon addition on diffusion of Cu in SH737-2Cu system was investigated. After compaction and transient liquid phase sintering at $1120^{\circ}C$ and $1180^{\circ}C$, samples were characterized for densification, showing rise in sintering density and reduction in swelling on carbon addition. Quantitative microstructural characterization (shape factor and pore size) revealed bimodal distribution for 0% carbon, more rounded pores for 0.9% carbon and higher sintering temperature, and pore coarsening at higher sintering temperature.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.9 no.1
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• pp.11-18
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• 2003

The pure $TiO_2$ particles have been prepared in vapor-phase hydrolysis of titanium tetraisopropoxide(TTIP). The rate of TTIP hydrolysis was so fast that the overall rate of formation of $TiO_2$ was controlled by the rate of mixing of TTIP and $H_2O$. Thus, the primary $TiO_2$ particles were prepared in nano sizes to form chainlike aggregates due to rapid coagulation. The pure $TiO_2$ particles as prepared were amorphous at the reactor set temperatures below $400^{\circ}C$ and became anatase at the temperatures of $450^{\circ}C$ above while the weak rutile peaks were also observed above $800^{\circ}C$. The actual size of primary particles as prepared were reduced by increasing the reactor set temperature while their crystalline sizes as well as BET sizes increased by post-sintering.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.4
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• pp.19-25
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• 2006

Thermal transient tests were performed on the electric initiator with STS 304 bridgewire(diameter 2.3 mil) and $Zr-KCIO_4$ primary charge. Analysing the test data using fitted Wire Model shows that the thermal characteristic parameter related to primary charge is changed sharply around $300^{\circ}C$. It is determined that this phenomenon is due to endothermic reaction from phase transition of $KCIO_4$, which is a component of the primary charge.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1638-1649
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• 2020

In the case of a severe accident in a Light Water Reactor, the issue of late release of fission products, from the primary circuit surfaces is of particular concern due to the direct impact on the source term. CsI is the main iodine compound present in the primary circuit and can be deposited as particles or condensed species. Its chemistry can be affected by the presence of molybdenum, and can lead to the formation of gaseous iodine. The present work studied chemical reactions on the surfaces involving gaseous iodine release. CsI and MoO₃ were used to highlight the effects of carrier gas composition and oxygen partial pressure on the reactions. The results revealed a noticeable effect of the presence of molybdenum on the formation of gaseous iodine, mainly identified as molecular iodine. In addition, the oxygen partial pressure prevailing in the studied conditions was an influential parameter in the reaction.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.30-36
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• 2000

A numerical study was conducted to investigate the effects of flow parameters in a entrained flow combustor on the flow characteristics. The computational model was based on the gas phase Eulerian equations of mass, momentum and energy. The code was formulated with RNG k-$\varepsilon$ model for turbulent flow. The calculation parameters were the magnitude of primary and secondary jet velocity and the height difference between primary and secondary jet. As the secondary jet velocity increased, the upper recirculation zone of the primary jet was strengthened. It was found that as the primary jet velocity increased, there was a critical jet velocity at which the size of upper and lower recirculation zone was changed.