• Transactions of the Korean hydrogen and new energy society
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• v.31 no.1
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• pp.82-88
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• 2020

Recently, a fuel reforming plant for supplying high purity hydrogen has been studied to increase the operation time of underwater weapon systems. Since steam reforming is an endothermic reaction, it is necessary to continuously supply heat to the reactor. A fuel reforming plant needs a methanol-O₂ catalytic burner to obtain heat and supply heat to the reformer. In this study, two types of designs of a catalytic burner are presented and the results are analyzed through the experiments. The design of the catalytic burner is divided into that the O₂ supply direction is perpendicular to the methanol flow direction (Design 1) and the same as the methanol flow direction (Design 2). In case of Design 1, backfire and flame combustion occurred in the mixing space in front of the catalyst, and in the absence of the mixing space, combustion reaction occurred only in a part of the catalyst. For above reasons, Design 1 could not increase the exhaust gas temperature to 750℃. In Design 2, no flashback and flame combustion were observed, the exhaust gas could be maintained up to 750℃. However, the O₂ distributor was exposed to high temperatures, resulting in thermal damage.

• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.7-12
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• 2013

As emission regulation for vehicle has been reinforced, many researches carried out for HCNG(hydrogen-natural gas blends) fuel to the conventional compressed natural gas (CNG) engine. However, abnormal combustion such as backfire, pre-ignition or knocking can be caused due to high combustion speed of hydrogen and it can result in over heating of engine or reduction of thermal efficiency and power output. In the present study, improvement of combustion performance was observed with HCNG fuel since it can extend a flammability limit. Knocking characteristics for CNG and HCNG fuel were investigated. Feasibility of HCNG fuel was evaluated by checking the knock margin according to excess air ratio. The operation of engine with HCNG was stable at minimum advance for best torque(MBT) spark timing and knock phenomena were not detected. However, it is necessary to prepare higher knock tendency since possibility of knock is higher with HCNG fuel.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.4
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• pp.391-399
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• 2022

Hydrogen is one of the energy carriers and has high energy efficiency relative to mass. It is an eco-friendly fuel that makes only water (H₂O) as a by-product after use. In order to use hydrogen conveniently and safely, development of production, storage and transfer technologies is required and attempts are being made to apply hydrogen as an energy source in various fields through the development of the technology. For transporting and storing hydrogen include high-pressure hydrogen gas storage, a type of storage technologies consist of cryogenic hydrogen liquid storage, hydrogen storage alloy, chemical storage by adsorbents and high-pressure hydrogen storage containers have been developed in a total of four stages. The biggest issue in charging high-pressure hydrogen gas which is a combustible gas is safety and the backfire prevention device is that prevents external flames from entering the tank and prevents explosion and is essential to use hydrogen safely. This study conducted a numerical analysis to analyze the performance of suppressing flame propagation of 2, 3 inch flame arrestor. As a result, it is determined that, where the flame arrestor is attached, the temperature would be lowered below the temperature of spontaneous combustion of hydrogen to suppress flame propagation.

• Journal of Distribution Science
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• v.13 no.10
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• pp.83-91
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• 2015

Purpose - The purpose of this study is to identify whether the operation of cultural centers in discount stores contributes to their profitability. Thus, this study is aimed at exploring how the lifestyles of customers who use the cultural centers influence their intention to use the discount stores. Specifically, the effect of shopping value on the correlation between the lifestyle types and usage intention of the customers were examined through a structured research model. To verify the effect, a survey on 139 customers of the Cultural Center of Nonghyup Hanaro Club's S branch was conducted and the valid questionnaires were used for analysis. Research design, data, and methodology - The findings are as follows. First, the lifestyles seeking self-realization had a positive effect on utilitarian value, and lifestyles seeking pop cultures had a positive effect on hedonic value. Second, the mediating effect of shopping value on the correlation between the lifestyle types and usage intention of the customers is as follows. Utilitarian value had a mediating effect only on the lifestyles seeking self-realization. In case of lifestyles seeking pop cultures, the use of Cultural Center had no effect on the intention to use the discount store. Third, an analysis of a revised research model revealed that the store usage intention of lifestyles seeking pop cultures can be enhanced by boosting the utilitarian value through hedonic value. Results - The findings suggest the following. Customers with lifestyles seeking self-realization, who value what is beneficial to them with little attention to the perceptions of others, are highly interested in the benefits they can gain from shopping. As for customers with lifestyles seeking pop cultures, they are highly likely to consume products popular in a particular culture such as new products and sports, based on financial stability they pursue. Thus, they prefer more subjective, personal experience, unlike consumers pursuing utilitarian value. Conclusions - As a result, the former pursues hedonic value gained in the process of shopping with fun and joy, rather than doing shopping with a particular purpose in mind. Therefore, Cultural Centers need to offer information that fits the lifestyles of the users so that they are more likely to use the discount stores. However, if the Cultural Centers offer unified, profit-driven products and information, just to increase their store sales, it can backfire, which occurred in the past. On the other hand, if they provide information that fits the lifestyles of the users, it can actually increase the sales. Also, the findings suggest that sophisticated marketing strategies that can boost the hedonic value of customers by linking the educational contents of Cultural Centers to actual shopping, which is beneficial to consumers, should be set and operated by discount stores. In particular, customers with lifestyles seeking self-realization can be encouraged to use the stores by making them recognize the utilitarian value. However, the use of Cultural Centers doesn't necessarily lead to higher sales among customers with lifestyles seeking pop cultures. As mentioned previously, unified marketing strategy is not as effective for Cultural Centers of large discount stores.

• Journal of Korean Society of Forest Science
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• v.79 no.3
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• pp.330-342
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• 1990

One might have a retrospect on the relationship between the forest and human being from the viewpoint of ecological perspective. It is no doubt that most of the fossil humans should have lived on the forest and the latter provided foods and shelters for humans from their beginning stages, Since the so-called agricultural revolution, humans have extensively started to exploit the forest which had beer, their cradle. The industrial revolution has created another situation against the forest in terms of the quality of ecosystem. These two revolutions have set up the so-called civilization which seems to have been based on the sacrificial oblation of the forest. The cradle for human being has been kept exterminating for the shake of "economic development and miracle." This might be a synoptic history of relationships between the forest and human beings in a sense. designates the behavioral aspects of human being against the forest and people consider the forest only as exploitable resource in this context, and the latter means that people live on the forest and strive to adapt the order of forest ecosystem. The resourcism has developed a strategy of colonialism to exploit the forest and provided a winner's position for the human beings against the forest, This idea and behavioral perspective seems to have started the backfire against the exploiter who is the owner of the civilization. However, there are different philosophies and ideas to view the relationship between the forest and human beings. People within the forest who are mostly considered as "primitives" still keep their idea of the ontology of the forest. There is a theoretical assumption of the "socionatural system" to look into the ecosystem. The forest could be viewed in the above frame of analysis. There are five variables : environment, resource, technology, organization, and ideology. Ideological aspect of the forest can be explained in the context of belief systems. Forest has a meaning of religion and rituals and people within the forest should admire it in anyway of religious reasons. This aspect of the forest cannot be separated from the environmental aspect of the forest. People within the forest acknowledge and practice the above idea. People outside the forest have lost the idea, however, at the cost of acquiring the civilization. They have expelled themselves from the forest and divided the socionatural system of the forest by way of colonialism. The efforts like agroforestry and social forestry would be strategies for recovering the idea of ontology of the forest as well as the sense of community including the forest and human being. People within the forest will be a prospective model for the future socionatural system of the forest for the people outside the forest. At this point, an ecological anthropologist can work with the forest specialists.