• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.2
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• pp.168-177
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• 2015

Shell waste from the butter clam Saxidomus purpuratus and littleneck clam Ruditapes philippinarum is a large by-product of shellfish aquaculture, and it is desirable to convert it into value-added products for industrial applications. In this study, calcium carbonate (CaC) polymorphs from butter clam (BCSP) and littleneck clam (LCSP) shell powders and commercial CaC were characterized using Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results revealed that the optimal calcination conditions to eliminate organic substances and improve solubility for both BCSP and LCSP were $800^{\circ}C$ for 8 h in an electrical furnace. Calcination improved the white index of the butter clam (BCCP) and littleneck clam (LCCP) calcined powder compared with shell powders. The calcium content in BCCP (51.1%) was higher than that of LCCP (44.9%) or commercial calcium oxide (CaO, 44.7%). The XRD patterns of BCCP and LCCP were similar to that of CaO. Cubic-like crystals of CaC and irregular crystals of BCCP and LCCP were observed by SEM. The FT-IR and XRD analyses revealed the presence of calcite and aragonite in the BCSP and aragonite in the LCSP, whereas the CaC contained calcite. These results indicate that butter and littleneck clam shells are potential biomass resources for calcium carbonate and calcium oxide.

• Journal of Korean Society for Quality Management
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• v.52 no.2
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• pp.275-286
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• 2024

Purpose: The spare part cost is one of the most important cost factors with which construct Life Cycle Cost. The LCSP(Life Cycle Sustainment Plan) Guidebook issued by Korea Ministry of Defense, however, suggests a simple equation to estimate the spare part cost using maintenance task frequencies and each part cost. Therefore, following the cost estimation method in the LCSP Guidebook may lead to an improper cost estimation result since both the hierarchical structure of the weapon system and the part discard rate are not considered. The purpose of this study is to develop a new life cycle cost estimation method for spare parts of weapon system during its life cycle. Methods: In this study, the detailed cost structure of spare parts is provided. Also a new spare part cost estimation methods for the each cost element are proposed, considering the hierarchical structure of weapon system and the part discard rate. And the proposed spare cost estimation methods are applied to K system for a case study. Results: Based on the case study of K system, the spare part cost estimation method, proposed by this study, shows that it can complement the estimation method suggested by the LCSP Guidebook. It also shows that it is applicable to the weapon systems for Korea armed forces. Conclusion: The proposed life cycle cost estimation method for spare parts has an advantage of estimating the spare part cost more accurately. It is expected to be useful in analyzing the procurement alternatives objectively and making up the Korea armed forces budget effectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.417-425
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• 2020

Recently, the development of weapons systems in conjunction with the Fourth Industrial Revolution has increased the number of weapon systems that integrate individual commercial systems by actively incorporating the superior fields of private commercial technologies. In the case of such commercial product-based weapons systems, however, the development of ILS elements across all areas, such as technical manual, military field maintenance support equipment, interactive electronic technical manual (IETM), and Computer Based Training (CBT) development, and weapons system Reliability, Availability, Maintainability(RAM) target values, and logistics support analysis (LSA) was requested to expand the level of development by developers. The commercial product-based System Integration (SI) weapon system will be able to complete the comprehensive military balance for complementing and effective maintenance of the military and developers only when the ILS development, which is limited to the essential elements of the required group, Request For Proposal (RFP) and Post-Logistics Support (PLS) directions were applied in the framework of outsourcing maintenance implementation. As a result, by checking the operation status of current weapons systems, the logistics support of commercial product-based weapon systems selected outsourcing as the basic policy that is decided based on the development requirements, focusing on maintaining operation through a rational decision-making process, and presented a plan for applying the development plan to the RFP for the determined core elements and PLS.