• Journal of the Korean Society of Safety
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• v.7 no.3
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• pp.35-42
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• 1992

Ignition energy effects of concentration of mixed gas In closed cylindrical vessel(1, 832㎤) are studied. The ignition energy ranged from 25 Joule to 110 Joule, and hidrogen and methane gases were used for flammable gas at stoichiometric condition with oxygen gas and nitrogen gas (N2) was for inert gas, which concentration was maximum 60% . The explosion pressure, temperature, concentration of product gases were calculated. It is found that - The explosion pressure and explosion velocity increase with ignition energy. - The gradience of explosion velocity with ignition energy is steeper than explosion pressure. - The results of calculation are similiar with results of experiment. - NOx is not serious product gas for methane and hydrogen gas, but CO is serious at certain concentration for methane in asphyxiation.

• YAKHAK HOEJI
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• v.18 no.1
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• pp.49-58
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• 1974

Tablet product design problem was structured as constrained optimization problem and subsequently solved by multiple regression analysis and Lagrangian method of optimization. Aluminum flufenamate was the drug chosen and microcrystalline cellulose nad starch were the binder and disintegrant, respectivley. The effect of the binder and disintegrant concentration on tablet hardness, friability, volume, in vitro release rate, and urinary excretion rate of drug in human subjects was recorded. Since a reasonably rapid release rate of drug is generally an important objective in the design of solid dosage form, optimization of this parameter was employed in studying the applicability of constrained optimization to a pharmaceutical product design problem. In addition to finding optimal sitivity analysis studies to such problems was also illustratd. It would appear that prediction of the in vivo t$_{50%}$ response from a knowledge of the incitro t$_{50%}$ response can be made fairly accurately for the tablet system used in this study.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.270-271
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• 2006

Nd-Fe-B type powder was sintered using spark plasma sintering method. Fabricated compact sintered at the temperature of $700\;^{\circ}C$, is found to be a composite magnet with Nd-Fe-Co-B and ${\alpha}-Fe$. The compact sintered at $700\;^{\circ}C$ shows slightly low coercivity and large remanent magnetization comparing to the compact sintered at $600^{\circ}C$ due to the formation of ${\alpha}-Fe$ phase, resulting in the large maximum energy product. Maximum energy product tends to decrease with decreasing thickness of sintered compacts below 0.5 mm in thickness.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.1
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• pp.23-32
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• 1997

The change in moisture content of moisture sensitive products in moisture-semipermeable packages was investigated for the purpose of predicting the shelf life of a product-package combination. A mathematical model, and a computer program based on the physiochemical properties of the product and the moisture permeability of the package was developed. The moisture content for products in moisture-semipermeable packages was determined under various environmental conditions and the results were compared with the predicted values by means of the simulation model. These experimental studies demonstrated that the prediction of the change in moisture content of packaged products over time by the simulation model is accurate, within a practical range of temperature and relative humidity values. The developed semi-empirical model is considered to have applications in industry, since it provides product shelf life information for a range of temperature and relative humidity conditions, with a limited number of experimentally obtained data points.

• Bulletin of the Korean Mathematical Society
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• v.53 no.2
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• pp.495-506
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• 2016

In this note we consider the monoid $\mathcal{PODI}_n$ of all monotone partial permutations on $\{1,{\ldots},n\}$ and its submonoids $\mathcal{DP}_n$, $\mathcal{POI}_n$ and $\mathcal{ODP}_n$ of all partial isometries, of all order-preserving partial permutations and of all order-preserving partial isometries, respectively. We prove that both the monoids $\mathcal{POI}_n$ and $\mathcal{ODP}_n$ are quotients of bilateral semidirect products of two of their remarkable submonoids, namely of extensive and of co-extensive transformations. Moreover, we show that $\mathcal{PODI}_n$ is a quotient of a semidirect product of $\mathcal{POI}_n$ and the group $\mathcal{C}_2$ of order two and, analogously, $\mathcal{DP}_n$ is a quotient of a semidirect product of $\mathcal{ODP}_n$ and $\mathcal{C}_2$.

• Asia Marketing Journal
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• v.22 no.3
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• pp.29-50
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• 2020

Although companies perform societal marketing activities across different cultural regions, previous research was predominantly centered on a specific cultural region-the West. To address this limitation in the literature, the current research examines societal marketing in the Chinese market considering cultural characteristics. China has become the largest market in the world with great potential growth for its vast consumer base. Since there is heterogeneity among regions in China, it is imperative to divide China into several markets for better understanding. Thus, this study investigates different responses of Chinese regional (coastal vs. inland) consumers toward Cause-related Marketing (CM). Our findings reveal that Chinese consumers, in general, prefer utilitarian CM products compared to hedonic CM products, which is the opposite result of findings of the previous research. Further, this was truer for consumers in inland regions, while coastal consumers did not display any preference by product type. The academic and practical implications, limitations, and directions for future research are discussed.

• Journal of Surface Science and Engineering
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• v.56 no.3
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• pp.185-191
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• 2023

The lifetime and corrosion resistance of the coating depends on its thickness and composition. We checked how the plating progressed according to the shape of the product to be plated. There was no significant difference in the composition or thickness of the plating according to the shape of the separately plated products. Samples of different shapes collected from products with complex shapes showed no significant difference in composition depending on the shape, but significant differences in thickness. This difference is due to the difference in applied current density depending on the shape of the product.

• Journal of the Korea Convergence Society
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• v.12 no.1
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• pp.133-141
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• 2021

This research suggests a design process that effectively complements the human-centered design through an objective data-driven approach. The subjective human-centered design process can often lack objectivity and can be supplemented by the data-driven approaches to effectively discover hidden user needs. This research combines the data mining analysis with co-design process and verifies its applicability through the case study on the smart heating jacket. In the data mining process, the clustering can group the users which is the basis for selecting the target groups and the decision tree analysis primarily identifies the important user perception attributes and values. The broad point of view based on the data analysis is modified through the co-design process which is the deeper human-centered design process by using the developed workbook. In the co-design process, the journey maps, needs and pain points, ideas, values for the target user groups are identified and finalized. They can become the basis for starting new product development.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1356-1358
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• 1995

About 20 years have passed since cross-linked polyethylene(XLPE) came into practical use for power transmission cables. In 1969, We were the first to product 33kV XLPE insulated cables, and in 1984 produced XLPE cable for 154kV. To meet the increasing demand for electric power in large cities, and to improve reliability of the power supply, plans are being made to introduce ultrahigh-tension power cable for long distance underground lines in urban areas. Studies are currently under way to develop more than 154kV XLPE cables to meet increasing demand. In this paper presents the progress in the production and design of XLPE cables, and describes ways in which further improvements seems likely.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.4
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• pp.515-522
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• 1993

The purpose of this study was to evaluate the bond strength of rebase resin to denture base resin. The denture base resins in this study were Premium Super-20(Lang Dental Mfg. Co. Inc., Wheeling, USA) and Lucitone 199(Dentsply International Inc., York, USA). And the rebase resins were Repair Acrylic(Lang Dental Mfg. Co. Inc., Wheeling USA). Toughron Rebase(Miki Chemical Product Co. Ltd., Japan) , Tokuso Rebase(Tokuyama Soda. Co. Ltd., Japan) and Triad VLC Reline Material(Dentsply International Inc., York, USA). The obtained results were as follows : 1. The bond strength of Repair Acrylic to Premium Super-20, and that of Toughron Rebase to Lucitone 199 were the highest. 2. In Premium Super-20 and Lucitone 199, bond strength of all rebase resins had significant differences. 3. The bond strength of Triad VLC Reline Material was inclined to the lowset.