• International Journal of Quality Innovation
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• v.9 no.1
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• pp.94-102
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• 2008

When facing the global severe competition, the enterprises all try their best to upgrade the quality, reduce the costs to reach the goal of customer satisfaction. Motorola was the earliest firm creating the term Six Sigma (6 ${\sigma}$); GE was the enterprise successfully fulfilling Six Sigma. The success of these two firms revealed the prominent effects and became the world-class model enterprises. The main purpose of promoting Six Sigma activity was to reduce the possible defects in the business process to the least through designing and monitoring business process in order to reach the goals such as the best quality and efficiency, the lowest costs, the shortest circular process time, maximum profits and customer satisfaction. This research used the Six Sigma technique to improve the business process of ceramics manufacturing plant and find out the major factors of slower core task time by the analytical process of Process Mapping, Pareto Chart, Simu18 simulation software and figures and proposed the improvement measures. Through the confirmation of the case companies, it successfully reduced the core process time and the organizational costs and increased the capacity.

• Journal of Computing Science and Engineering
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• v.5 no.4
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• pp.283-287
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• 2011

Due to the proliferation of software parallelization on multi-core CPUs, the number of concurrently executing processes is rapidly increasing. Unlike processes running in a server environment, those executing in a multi-core desktop or a multi-core mobile platform have various correlations. Therefore, it is crucial to consider correlations among concurrently running processes. In this paper, we exploit the property that for a given created location in the binary image of the parent process, the average running time of child processes residing in the run-queue differs. We claim that this property can be exploited to improve the overall system performance by running processes that have a relatively short running time before those with a longer running time. Experimental results verified that the running time was actually improved by 11%.

• Journal of the Korea Society of Computer and Information
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• v.20 no.9
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• pp.1-10
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• 2015

In this paper, we propose a new variable latency L1 data cache architecture for multi-core processors. Our proposed architecture extends the traditional variable latency cache to be geared toward the multi-core processors. We added a specialized data structure for recording the latency of the L1 data cache. Depending on the added latency to the L1 data cache, the value stored to the data structure is determined. It also tracks the remaining cycles of the L1 data cache which notifies data arrival to the reservation station in the core. As in the variable latency cache of the single-core architecture, our proposed architecture flexibly extends the cache access cycles considering process variation. The proposed cache architecture can reduce yield losses incurred by L1 cache access time failures to nearly 0%. Moreover, we quantitatively evaluate performance, power, energy consumption, power-delay product, and energy-delay product when increasing the number of cache access cycles.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.12
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• pp.28-32
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• 2010

Technical demands for aspheric glass lens formed in market increases its application from simple camera lens module to fiber optics connection module in optical engineering. WC is often used as a metal core of the aspheric glass lens, but the long life time is issued because it fabricated in high temperature and high pressure environment. High hard thin film coating of lens core increases the core life time critically. Diamond Like Carbon(DLC) thin film coating shows very high hardness and low surface roughness, i.e. low friction between a glass lens and a metal core, and thus draw interests from an optical manufacturing industry. In addition, DLC thin film coating can removed by etching process and deposit the film again, which makes the core renewable. In this study, DLC films were deposited on the SiC ceramic core. The process variable in FVA(Filtered Vacuum Arc) method was the substrate bias-voltage. Deposited thin film was evaluated by raman spectroscopy, AFM and nano indenter and measured its crystal structure, surface roughness, and hardness. After applying optimum thin film condition, the life time and crystal structure transition of DLC thin film was monitored.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2865-2870
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• 2013

Ni-Ag core-shell nanoparticles were synthesized by polyol process and microemulsion technique successfully. In the polyol process, a chemical reduction method for preparing highly dispersed pure nickel and Ag shell formation have been reported. The approach involved the control of reaction temperature and reaction time in presence of organic solvent (ethylene glycol) as a reducing agent for Ag cation with poly(vinyl-pyrrolidone) (PVP. Mw = 40000) as a capping agent. In microemulsion method, the emulsion was prepared by water/cetyltrimetylammonium bromide (CTAB)/cyclohexane. The size of microemulsion droplet was determined by the molar ratio of water to surfactant (${\omega}_o$). The core-shell formation along with the change in structural phase and stability against oxidation at high temperature heat treatments of nanoparticles were investigated by X-ray diffraction and TEM analysis. Under optimum conditions the polyol process gives the Ni-Ag core-shell structures with 13 nm Ni core covered with 3 nm Ag shell, while the microemulsion method gives Ni core diameter of 8 nm with Ag shell of thickness 6 nm. The synthesized Ni-Ag core-shell nanoparticles were stable against oxidation up to $300^{\circ}C$.

• The Korean Journal of Rheology
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• v.11 no.2
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• pp.159-167
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• 1999

Sandwich injection molding is one of the remarkable polymer processes recently developed from conventional injection molding. But it is almost impossible to do theoretical investigation that we've researched it through numerical simulation. In this paper, numerical simulation on the study of sandwich injection molding is based on Finite Element Method and FAN/Control Volume method. In addition to conventional filling parameter that can confirm skin polymer melt front, new filling parameters have been introduced to confirm core polymer melt front advancement. These filling parameters are defined in each layer which is divided to solve temperature field along the thickness direction. One can notice different filling patterns resulted from the variation of material properties such as viscosities and power-law indexes, and processing conditions such as switch-over times and wall temperatures. It gives us a better understanding of the sandwich injection molding process. And we can recognize that it's the core polymer spatial distribution after the completion of filling that is the most important key point to use this process for industrial molding process.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.3
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• pp.211-216
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• 2014

Corrosion products are released to the primary coolant in the corrosion process of structural materials. They are deposited on fuel surfaces and activated on exposure to a neutron flux with formation of radionuclides that can become incorporated into out-of-core surface films. To get a clear understanding of activated crud formation process, the specific activity and core residence time of fuel cruds was calculated as a function of exposure time to the core neutron flux on the assumption that parent nuclide is being deposited continuously. Fuel cruds were sampled in the fuel scraping campaign from Hanul Unit 1 Cycle 17 and analyzed for elemental concentration and radioisotope activity.

• Ceramist
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• v.21 no.4
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• pp.427-432
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• 2018

In this study, the aspherical lens for optical communications produced not with an one-step pneumatic type of external pressurization system (existed GMP process) but a constant weight of self-loaded mold put up to upper core. So the lens is molding with self-loaded weight molding and it calls Weight Molding process. In self-loaded molding process, we measured changes of center thickness molding lenses with each variable molding temperatures and time to find the effect of center of lens thickness to search key factors. As experimental results, the center thickness reach to targeted lenses step time value was changed drastically and it depends by molding temperature. If the molding temperature gets higher, the targeted lens that is reaching to the center thickness step time value was decreased. To find the effect of life improvement on mold core by imposing the self-loaded molding process we molded with GMP(Glass molding press) method and self-loaded molding method for 9,000 times and measured the lenses shape accuracy and surface roughness to evaluate the core life. As a result the self-loaded molding method core has 2,000 times longer that GMP (Glass molding press) method. If we adopt self-loaded molding method of the optical aspherical lens molding in the future, we expect that it would reduce the expense of changing the molds by molding core life improvements.

• Design & Manufacturing
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• v.8 no.2
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• pp.41-45
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• 2014

Automated polishing apparatus based on the research have been developed. The research is improvement of polishing process for surface quality and uniformity improvement of preform injection mold core. Surface quality of preform core have influence on ejecting and product quality after injection molding. Thus, the current being made by hand to automate the polishing process, the surface of the preform to improve the quality and uniformity improvement. First made a division by analyzing manual process a step-by-step. And draw a mechanism for converting mechanical movement. Automated polishing apparatus for preform core was developed, through which shortens production time and were able to secure the safety of the worker.

• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.113-118
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• 2022

Multifunctional nanomaterials based on mesoporous silica nanoparticles (MSN) and metal oxide nanocrystals are among the most promising materials for theragnosis because of their ease of modification and high biocompatibility. However, the preparation of multifunctional nanoparticles requires time-consuming multistep processes. Herein, we report a simple one-pot synthesis of multifunctional Mn₃O₄/mesoporous silica core/shell nanoparticles (Mn₃O₄@mSiO₂) involving the temporal separation of core formation and shell growth. This simple procedure greatly reduces the time and effort required to prepare multifunctional nanoparticles. Despite the simplicity of the process, the properties of nanoparticles are not markedly different from those of core/shell nanoparticles synthesized by a previously reported multistep process. The Mn₃O₄@mSiO₂ nanoparticles are biocompatible and have potential for use in optical imaging and magnetic resonance imaging.