• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.636-642
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• 2022

The "Hydrogen Economic Activation Road map" was announced in 2019, and hydrogen demand is expected to exceed 470,000 tons per year in 2022 and keep increasing. Under this circumstance, it has become important to understand the greenhouse gas (GHG) emissions associated with various hydrogen production pathways. In this study, the evaluation of life cycle GHG emissions regarding the hydrogen produced as by-product from coke oven gas (COG) in steel mill is conducted. To cover the possible range of operations, three literatures were reviewed and their data of inputs and outputs for the process were adopted for calculation. Life cycle inventories and emission factors were mostly referred to GaBi and Intergovernmental Panel on Climate Change (IPCC) guidelines, respectively. When there are multiple products from a single process, the energy allocation method was applied. Based on these sources and the assumptions, the life cycle emission values of COG-based hydrogen were found to be 3.8 to 4.7 kg/CO₂-eq./kg-H₂.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.12
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• pp.543-548
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• 2017

In recent years, the importance of the safety of medical device software has been emphasized because of the function and role of the software among components of the medical device, and because the operation of the medical device software is directly related to the life and safety of the user. To this end, various standards have been set up that provide activities that can effectively ensure the safety of medical devices and provide their respective requirements. The activities that standards provide to ensure the safety of medical device software are largely divided into the development life cycle of medical device software and the risk management process. These two activities should be concurrent with the development process, but there is a limitation that the risk management requirements to be performed at each stage of the medical device software development life cycle are not classified. As a result, developers must analyze the association of standards directly to develop risk management activities during the development of medical devices. Therefore, in this paper, we analyze the relationship between medical device software development life cycle and risk management process, and extract risk management requirement items. It enables efficient and systematic risk management during the development of medical device software by mapping the extracted risk management requirement items to the development life cycle based on the analyzed associations.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.323-327
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• 2006

In this paper, the methodology of life-cycle assessment was applied to an ethanol production process based on catalytic reaction. The environmental performance of the process was quantified and compared with that of the fermentation process. The purpose of the assessment was to develop design guidelines for the environmentally better ethanol production. The assessment was carried only on the stages of raw material acquisition through ethanol manufacture since it was assumed that ethanol from two processes had the same environmental impacts through its use and discard. The inventory analysis of the catalytic process resulted in that carbon dioxide from methanol production was the major environmental impact. The impact assessment showed that the fermentation process was environmentally better than the catalytic one. Suggestions for environmental improvement of the catalytic process were prepared based on the assessment results.

• Environmental Engineering Research
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• v.25 no.1
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• pp.52-61
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• 2020

The article examines the impact differences between producing concrete and asphalt. Both materials are widely used in the construction industry. Construction activities account for a large portion of greenhouse gases. Therefore, it is important to consider the Life Cycle Analysis (LCA) to reduce environmental impacts. In this study, the material processes were inputted into an LCA program called SimaPro. The database used for the study was Ecoinvent as it is one of the major databases within SimaPro. The materials were compared against impacts per kg of material produced as the functional unit. Each process was created using the materials, energy and transportation required to produce the materials. Waste streams were also included in the process to determine the impacts after the product was done with its useful life. Using the ReCiPe method, an LCA was conducted. Midpoint and endpoint categories were examined for both the productions. The processes had similar results for the human health and ecosystems categories; however asphalt was marginally higher for both. Asphalt had exceeded concrete in the resource impact category by 100 mPt. The results indicate that concrete is the more sustainable building material. Determination of various impacts of the materials is important for material selection.

• Korean Journal of Metals and Materials
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• v.50 no.7
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• pp.517-522
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• 2012

In this study, a super carburizing treatment was applied to improve roller pitting fatigue life. It produced excellent properties of surface hardness and temper softening resistance by forming precipitation of fine and spherodized carbides on a tempered marstensite matrix through the repeated process of carburization and diffusion after high temperature carburizing step 1. The cycle II performed two times carburizing/diffusion cycle (process) after super carburization at $1,000^{\circ}C$ had fine and spherodized carbides to subsurface $200{\mu}m$. In this case, the carbide was $(Fe,Cr)_3C$ and there was not any massive carbides. In the case of Cycle II, the roller pitting fatigue life had a 6.15 million cycles. It was improved 48% compared to normal gas carburizing treatment.

• Journal of Applied Biological Chemistry
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• v.51 no.6
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• pp.262-271
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• 2008

Natural abundances of stable isotopes of nitrogen and carbon (${\delta}^{15}N$ and ${\delta}^{13}C$) are being widely used to study N and C cycle processes in plant and soil systems. Variations in ${\delta}^{15}N$ of the soil and the plant reflect the potentially variable isotope signature of the external N sources and the isotope fractionation during the N cycle process. $N_2$ fixation and N fertilizer supply the nitrogen, whose ${\delta}^{15}N$ is close to 0%o, whereas the compost as. an organic input generally provides the nitrogen enriched in $^{15}N$ compared to the atmospheric $N_2$. The isotope fractionation during the N cycle process decreases the ${\delta}^{15}N$ of the substrate and increases the ${\delta}^{15}N$ of the product. N transformations such as N mineralization, nitrification, denitrification, assimilation, and the $NH_3$ volatilization have a specific isotope fractionation factor (${\alpha}$) for each N process. Variation in the ${\delta}^{13}C$ of plants reflects the photosynthetic type of plant, which affects the isotope fractionation during photosynthesis. The ${\delta}^{13}C$ of C3 plant is significantly lower than, whereas the ${\delta}^{13}C$ of C4 plant is similar to that of the atmospheric $CO_2$. Variation in the isotope fractionation of carbon and nitrogen can be observed under different environmental conditions. The effect of environmental factors on the stomatal conductance and the carboxylation rate affects the carbon isotope fractionation during photosynthesis. Changes in the environmental factors such as temperature and salt concentration affect the nitrogen isotope fractionation during the N cycle processes; however, the mechanism of variation in the nitrogen isotope fractionation has not been studied as much as that in the carbon isotope fractionation. Isotope fractionation factors of carbon and nitrogen could be the integrated factors for interpreting the effects of the environmental factors on plants and soils.

• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.11-24
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• 2012

Recently, BIM (Building Information Modeling) technique is being considered as a critical delivery condition for the public projects according to the increase of best practices by practical application of BIM. However, since existing BIM studies are focused on the design and construction phases, those results are not considering the life cycle of a construction project. Therefore, this study suggests an integrated BIM operation process that enables an application of BIM for each phase of a construction project from planning to maintenance phases and develops an integrated BIM system based on the suggested methodologies. This study developed basic BIM functions and its application process by analyzing information systems in each project phase for a bridge construction project. Besides, this study performed case study and survey analysis for construction managers to verify a practical applicability of the developed system. Therefore, it is expected that the integrated BIM system is going to be utilized as a 3D-based integrated information management system considering life cycle of construction projects.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.5
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• pp.805-826
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• 2022

This study explored the process by which consumers purchase products from small fashion business owners via online and mobile channels. In addition, group types were classified given that the purchasing process depends on the consumers' life cycle. The consumer focus group interview (FGI) was conducted on 18 participants that were divided into six groups by age, work, and children. Results revealed that first, consumer journey comprised four stages. Factors influencing need recognition were "attention to information of social media influencer," "attention to information of affiliated groups," and "repeated advertising of SME products/brands." For information searching, "exploring purchase reviews," "environment for mobile shopping information exploration," and "continuous product tracking" were important factors. Purchasing and shopping stages were affected by "price-free, improvised purchase decision" and "convenient mobile payment system and point benefits." After the purchase, "active sharing and repeated purchase when satisfied" and "blocking relationships when dissatisfied" occurred. Second, six consumer groups based on the fashion life cycle are the "Platform lover," "Influencer follower," "Trust builder," "Novelty seeker," "Convenience seeker," and "New designer supporter." Ultimately, small business owners can develop the process of planning and selling fashion products more efficiently.

• Culinary science and hospitality research
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• v.2
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• pp.59-87
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• 1996

This study has been done by giving the guide when development of menu or doing marketing strategy in Hotel Restaurant. All products and service has a regular course from induction in market to disappear, so it shall be come out Products Life Cycle theory. In eating business, under the tendency and existing cycle to change menu by taste of customers, liking variation, change of periodic status (environment), MLC(Menu Life Cycle) shall be advised by application PLC(Products Life Cycle) in the process of induction of some menu first and spreading the same business field and then deletion (disappearance) from menu because of no popular. In Emergence Stage, it shall be tried to inform new menu through Cooking Contest, presentation of new menu, free sampling party and others. In Growth Stage, it shall be changed package menu or set menu. In Maturity Stage, it shall be provided complimentary ticket, gift coupon or discount for the customers with some degree of selling record in order to increase using frequency and selling amount after insure new customers. In Decline Stage, it shall be groped for entry underdeveloped country or less advance nation, but there is no possibility to devote in enterprise, it shall be planned substitute menu development in order to withdraw. By inducting MLC concept, it shall be provided the available informations such as“how could some menu be circulate in some restaurant”“Accordingly do strengthen promotion activities or go to low developed area or overseas, or delete it from menuitems and so on”. In the time of decline some menu, it is judged to the time of plan(preparation) of new menu development. In the broad view, when consideration of the concept of menu life cycle, it shall be possible to know which menu is decayed and which menu is developed newly or grown-up, so it shall be provided the important information to estimate the tendency of changing menu and set-up a menu development plan.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2262-2269
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• 2010

A recent Tilting train development operation for existing line high speed, already developed "Korean Tilting Train eXpress(bellow TTX)" and that doing demonstration of operation. And TTX are going to commercial service in 2012. They are preparing Environmental Declaration of Product(bellow EDP) for offering environmental impact of TTX to customer. EDP calculated environmental impact of target product's whole life cycle(raw material and manufacturing, distribution, use, end of life) more quantity for that improving environmental impact and then certification them, it is using for that estimate some part of existence of specific pollutants, GHGs, energy consumption and recycling ratio. In this study, 1) analyze the process of getting EDP, 2) satisfy common criteria and each criteria(plan) in the Product Category Rules(bellow PCRs) provided KEITI, 3) according to ISO 14044, implementation of LCA. 4) These results be shown Characterized Impact(bellow CI) about each life cycle stage and six impact categories(ARD, GWP, OD, AD, EU, POC).