• Proceedings of the Safety Management and Science Conference
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• 2006.11a
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• pp.373-383
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• 2006

Logistics is one of the most important factors to manage a stream of materials in economic environment. Establishing effective logistics system needs to consider some constraints which are fluctuation of materials volume, a long distance between makers and consumers, one way logistics and small quantity batch production. It is estimated that Unit Load System should be a powerful method to cope with those problems. It helps to realize the key issues which are Standardization and Logistics Pool System The Material Unification of Logistics System is able to participate in all kinds of industries including manufacturing, distribution and logistics. This system has some merits which are a long distance transportation cost down, product recovery, and treatment in the unbalance of demand and supply caused by unstable materials volume. Four strategies of Material Logistics Model are Packing Rationalization, Logistics Pool System, JIT System application and establishing effective infrastructure. The Material Unification Of Logistics System based on Unit Load System achieves efficiency of logistics and largely decreases moving cost.

• Corrosion Science and Technology
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• v.20 no.1
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• pp.15-21
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• 2021

Through a simple filtration process, followed by carbonization within a reductive environment, coffee waste grounds can be transformed into a non-porous hard carbon for use in multiple contexts. This resulting coffee-waste carbon has been evaluated as an eco-friendly and cost-effective replacement for conventional graphite. When compared with different types of carbon, our study found that the coffee-waste carbon fell into the category of hard carbon, as verified from the galvanostatic charge/discharge profiles. The coffee-waste carbon showed a superior rate capability when compared to that of graphite, while compromising smaller capacity at low C rates. During electrochemical reactions, it was also found that the coffee-waste carbon is well exposed to electrolytes, and its disordered characteristic is advantageous for ionic transport which leads to the low tortuosity of Li ions. Finally, the high irreversible capacity (low initial Coulombic efficiency) of the coffee-waste carbon, which if also often observed in amorphous carbon, can be adequately resolved through a solution-based prelithiation process, thereby proving that the coffee-waste carbon material is quite suitable for commercial use as an anode material for quickly-chargeable electrodes.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.145-145
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• 2021

Water distribution networks (WDNs) are designed to satisfy water requirement of an urban community. One of the central issues in human history is providing sufficient quality and quantity of water through WDNs. A WDN consists of a great number of pipelines with different ages, lengths, materials, and sizes in varying degrees of deterioration. The available annual budget for rehabilitation of these infrastructures only covers part of the network; thus it is important to manage the limited budget in the most cost-effective manner. In this study, a novel pipe replacement scheduling approach is proposed in order to smooth the annual investment time series based on a life cycle cost assessment. The proposed approach is applied to a real WDN currently operating in South Korea. The proposed scheduling plan considers both the annual budget limitation and the optimum investment on pipes' useful life. A non-dominated sorting genetic algorithm is used to solve a multi-objective optimization problem. Three decision-making objectives, including the minimum imposed LCC of the network, the minimum standard deviation of annual cost, and the minimum average age of the network, are considered to find optimal pipe replacement planning over long-term time period. The results indicate that the proposed scheduling structure provides efficient and cost-effective rehabilitation management of water network with consistent annual budget.

• Solar Energy
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• v.2 no.2
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• pp.37-53
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• 1982

In general, glass has proven to be an effective glazing material, exhibiting extended service lifetime and high solar transmittance while remaining opaque to long wave thermal reradiation. Plastics, which possess higher solar transmittance than commercial glass, are lightweight and also cost competitive with glass. In this paper a survey of various glazing materials is presented, and the comparative analysis of their properties are perform ed in detail with special emphasis on double glazing materials, which can be adaptable to various passive solar systems.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1689-1691
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• 2006

DuPont Displays has developed a new solution printing fabrication process for OLED displays, using small molecule OLED materials. The new manufacturing process is more cost-effective and scalable than evaporation of materials through physical masks, and addresses issues associated with ink jet printing. A new material (DB) has been developed for use as a hole-injection layer in OLEDs.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.138-139
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• 2002

Polymer-bonded magnetostrictive composites have some distinct advantages over conventional type materials in being cost effective and suitable for high frequency applications due to high electrical resistivity. Composites of rare earth based alloys were reported to show good magnetostrictive characteristics both in static and dynamic conditions [1]. It was originally thought that the application of the polymer-bonding technique to transition metal alloys is straightforward. (omitted)

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.183-190
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• 1996

Leak-before-break(LBB) approach has been shown to be both cost and risk effective by reducing maintenance cost and occupational exposure when applied to high energy piping in nuclear power plants. For Korean Next Generation Reactor(KNGR) development, LBB is considered for the Main Steam Line(MSL) piping inside containment. Unlike the reactor coolant piping leakages which can be detected by particulate and gaseous radiation monitoring, main steam line leak detection systems must be based on principles that do not involve radioactivity. Ceramics are widely used as humidity sensor materials which can be further developed for nuclear applications. In this paper, we describe the progress in the development of ceramic humidity sensors for use with the main steam lines of KNGR.

• Journal of the Korean institute of surface engineering
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• v.56 no.3
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• pp.192-200
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• 2023

Graphene, a two-dimensional material, has shown great potential in a variety of applications including microelectronics, optoelectronics, and graphene-based batteries due to its excellent electronic conductivity. However, the production of large-area, high-quality graphene remains a challenge. In this study, we investigated graphene growth on electrolytic copper foil using thermochemical vapor deposition (TCVD) to achieve a similar level of quality to the cold-rolled copper substrate at a lower cost. The combined effects of pre-annealing time, graphenized temperature, and partial pressure of hydrogen on graphene coverage and domain size were analyzed and correlated with the roughness and crystallographic texture of the copper substrate. Our results show that controlling the crystallographic texture of copper substrates through annealing is an effective way to improve graphene growth properties, which will potentially lead to more efficient and cost-effective graphene production. At a hydrogen partial pressure that is disadvantageous in graphene growth, electrolytic copper had an average size of 8.039 ㎛², whereas rolled copper had a size of 19.092 ㎛², which was a large difference of 42.1% compared to rolled copper. However, at the proper hydrogen partial pressure, electrolytic copper had an average size of 30.279 ㎛² and rolled copper had a size of 32.378 ㎛², showing a much smaller difference of 93.5% than before. This observation suggests this potentially leads the way for more efficient and cost-effective graphene production.

• Journal of the Korean Ceramic Society
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• v.56 no.2
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• pp.130-145
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• 2019

Widespread commercialization of solid oxide fuel cells (SOFCs) is expected to be realized in various application fields with the advent of cost-effective fabrication of cells and stacks in high volumes. Cost-reduction efforts have focused on production yield, power density, operation temperature, and continuous manufacturing. In this article, we examine several issues associated with processing for SOFCs from the standpoint of the bimodal packing model, considering the external constraints imposed by rigid substrates. Optimum compositions of composite cathode materials with high volume fractions of the second phase (particles dispersed in matrix) have been analyzed using the bimodal packing model. Constrained sintering of thin electrolyte layers is also discussed in terms of bimodal packing, with emphasis on the clustering of dispersed particles during anisotropic shrinkage. Finally, the structural transition of dispersed particle clusters during constrained sintering has been correlated with the structural stability of thin-film electrolyte layers deposited on porous solid substrates.

• Advances in Computational Design
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• v.3 no.1
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• pp.49-69
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• 2018

This paper shows an optimal design for reinforced concrete rectangular combined footings based on a criterion of minimum cost. The classical design method for reinforced concrete rectangular combined footings is: First, a dimension is proposed that should comply with the allowable stresses (Minimum stress should be equal or greater than zero, and maximum stress must be equal or less than the allowable capacity withstand by the soil); subsequently, the effective depth is obtained due to the maximum moment and this effective depth is checked against the bending shear and the punching shear until, it complies with these conditions, and then the steel reinforcement is obtained, but this is not guaranteed that obtained cost is a minimum cost. A numerical experimentation shows the model capability to estimate the minimum cost design of the materials used for a rectangular combined footing that supports two columns under an axial load and moments in two directions at each column in accordance to the building code requirements for structural concrete and commentary (ACI 318S-14). Numerical experimentation is developed by modifying the values of the rectangular combined footing to from "d" (Effective depth), "b" (Short dimension), "a" (Greater dimension), "${\rho}_{P1}$" (Ratio of reinforcement steel under column 1), "${\rho}_{P2}$" (Ratio of reinforcement steel under column 2), "${\rho}_{yLB}$" (Ratio of longitudinal reinforcement steel in the bottom), "${\rho}_{yLT}$" (Ratio of longitudinal reinforcement steel at the top). Results show that the optimal design is more economical and more precise with respect to the classical design. Therefore, the optimal design presented in this paper should be used to obtain the minimum cost design for reinforced concrete rectangular combined footings.