• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.8
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• pp.733-741
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• 2013

This is the first paper on the combustion characteristics of landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine, and it discusses the fundamental characteristics of fuel from the viewpoint of thermochemistry and thermodynamics and compares these results with experimental ones. The results show that the final pressures obtained from theoretical analysis vary under the same heating value owing to the change in the constant volume specific heat owing to the difference in the burned gas composition according to the fuel gas compositions; furthermore, the stoichiometric ratios and trends of analytical and experimental pressures coincide very well, although some minor differences are observed between the two. The root cause of the difference is the heat transfer, which changes the specific heat and lowers the temperature considerably, in the real combustion process. In addition, the large chamber volume and ignition position promote the heat transfer to the wall. Finally, the fuel conversion efficiency increases as the methane mol fraction decreases, and it is maximum when the stoichiometric ratio ranges from 0.8 to 0.9. These increases due to the composition and stoichiometric ratio could sufficiently compensate the decrease due to the specific heat ratio drop, LFG might be more advantageous than pure methane in a real engine.

• Journal of the Korean Geographical Society
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• v.47 no.5
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• pp.735-754
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• 2012

Korean society in the 2000 has experienced new many social and spatial issues such as the process of neoliberalism and changes in urban and spatial policies, the development of information and communication technology and reconfiguration of informational social space, radically increasing foreign immigrants and transformation to multicultural society, global warming and environmental injustice, and these new issues have promoted development of social geography in Korea. In addition to a review on them, this paper provides a review on empirical researches on traditional issues which have been dealt with in social geography in the 2000 in Korea. Even though there have been numerous sub-issues, they can be divided into two categories: one is urban and communal social geography including urban housing and residential segregation, urban social problems such as poverty, crime, education, health care, social welfare, urban and rural community building, identity, sense of place, and social movement; the other is social geography of population and migration, including population movement, aged society and social welfare for elderly people, and foreign immigrants and formation of multicultural social space. As some difficult conditions such as path-dependent process of neoliberalism, transformation toward informational, aged, and multicultural society would continue, so social geography in Korea to tackle with these external conditions should deepen its theoretical insights and widen its research issues.

• Journal of The Korean Association For Science Education
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• v.40 no.5
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• pp.531-542
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• 2020

The purpose of this study is to explore the research trend changes of convergence education since 2011 compared to the convergence education research that has been steadily continuing in science education. The trend in convergence education were investigated by comparing the number of publications, research subjects, research content, and topic linkages with previous studies, and using the network analysis method to check recent research trends. In the field of science education, the number of papers related to convergence education has been published more than 8.0% steadily, and it has been increasing since 2012, then decreasing again from 2015 and gradually increasing again from 2017. The subjects of study were high in elementary school students, while those in middle school, high school, and university students were low. While the number of in-service teachers increased, the number of pre-service teachers decreased, and the literature and public increased somewhat. In study content, effectiveness studies decreased, while development studies increased, and theoretical and perception studies appeared similar. In thematic linkage, the intra-science linkage was 23.9%, and the extra-science linkage was 76.1% and engineering/technology and art were high in extra-science linkage. In network analysis, elementary, science, STEAM, and program words have a high frequency of appearance and appear together with other words to lead the network. The educational implications of the research trend of convergence education will be more emphasized in the field of science education in the future, and in order to take root in the education field, research on secondary students should be more actively studied. In addition, it is necessary to move away from research on STEAM-centered program development and effects, and to increase research to establish the philosophical basis and theoretical of convergence education.

• Journal of the Ergonomics Society of Korea
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• v.35 no.4
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• pp.205-223
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• 2016

Objective:This study introduced the status of studies and the projects related with agricultural accident prevention carried out by the Rural Development Administration. This study was conducted to promote Korean farmers' agricultural safety activation by analyzing study trends on farmers' agricultural work safety. Background: Agriculture is one of the dangerous industries, and the agricultural accident rate is on the rise, due to recent serious aging and increased female work force. Such a phenomenon emerges as a serious problem from the social perspective, and therefore measures for farmers' healthy and safe agricultural activities and accident prevention are required. Method: This study conducted literature review related with domestic and international agricultural safety and health. This study also examined the hazard factors of agricultural labor and injuries, agricultural safety and health system and policy, support and education for farmers' safety practice, and the status of convenience tools and protection equipment, based on major study activities performed by the Rural Development Administration for recent four to five years. Results: Through the study results, the status of Korea's agricultural safety system, compensation support policy, safety education of farmers for actual practice, and diverse channels including media were confirmed. This study also presented the R&D implementation status on convenience equipment and protective gear to prevent agricultural diseases and safety accidents. Conclusion: This study found out that continuous monitoring and efforts are required to prevent accidents for the Korea's agricultural labor environment and agricultural safety, and that social bond of sympathy formation is demanded through effect analysis on the implemented projects including education and support projects. Furthermore, it can be understood that agricultural accident prevention should be carried out through shift from current government-led top down approach to bottom-up approach from itself. Application: The results of this study can be utilized as useful data for farmers' safety and health.

• The Journal of Fisheries Business Administration
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• v.24 no.1
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• pp.65-86
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• 1993

In this paper, fishery economics is reviewed to extend a basic opportunity for developing new fishery economics and to evaluate the effects of the import liberalization on the fish trade structure of Korea. The principle outline of extensions emphasis to realize the modern fishery problems based on fishery economics and develop the practical methodology in order to analyze the impacts of the import liberalization on the fishery and fishermen welfare. During the process of export - oriented industrilization, the role and position of fishery in the economy is changed dynamically. When faced with the imperative of the role and position of fishery in the economy, fishery economists and domestic policy makers must decide how to organize themselves for solving fishery problems under the new regime in the import liberalization on the fish trade. Fishery problems impacted by the new regime can not be solved by fishery itself but be solved by the centralized efforts of all contributors in national views. Therefore the new systematic analytical methodology must be develop and the traditional fishery economics must be related to the regional development strategy and fishery sociology as subsidiary theories specialized. Due to the impacts of the import liberalization on the fish trade structure, fishery economists face with radical changes in the domestic fishery : a place of the resources harvest to place of the combination resource harvest and its demand, a fishing as a resource exploitation to a fishing as a resource management, a traditional small scale costal fishing to a modernized and scaled fishing, fishery using the given natural resource itself to fishery as technology intensive industry, and a food supply industry to a welfare indusry based on the regional and economic resource and social environment. As these changes, fishery and its community's regional and economic resource and social environments as multiple roles of the regional economic development are emphasized in fishery economics under the new regime in the import liberalization on the fish trade. Furthermore, domestic policy makers and administrators in a public sector must realize the above radical changing trends in fishery and understand a social and economic environment in fishery and develop a new fishery structure focusing on the fishing system and the fishery laws. As this point, they make efforts to improve and develop fishery as a food supply industry. Japan, for example, has a non - governmental organization to conflict the problem of international fishery such as a movement of a civil environmental protection. Also fishermen in Japan already realized conservation and pollution problems in fishing as fundamental issues of human being.

• Spatial Information Research
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• v.11 no.1
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• pp.41-60
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• 2003

It is noted that the paper mapping system for University Building Facility has many limitations in terms of data maintenance, real-time GIS data acquisition, and economic efficiency. The aim of this research was to evaluate an operational potential of an on site real-time mobile GIS technique to resolve the problem faced in the university. The idea is based upon the recent trends in the field of 'Telecommunication and Information Technology' that uses a PDA (personal Digital Assistants), wireless network computing, mobile computing, etc. A real time mobile GIS approach has been adopted, in which a PDA is linked to a wireless internet and field workers record data on the computer at the site and analyse data on site. While there should be a considerable number and variety of factors associated with real-time mobile GIS quality, this research focuses on three criteria that are identified as fundamental to customer requirements; (1) data quarry (2) spatial analysis (3) real-time GIS database building. 'Art--empirical study for a case study facility has been conducted to confirm the validity for the system. The system has been checked experimentally, enabled the field users to quarry the data required simply and execute spatial analysis (buffer, overlay etc.,) accommodating versatile alternatives on the site. Detailed visual maps can be generated over large areas quickly and easily. The PDA interface, in particular, were ideally suited for field users to interactively displaying positional information with attribute data. This system has shown to be quite convenient to maintaining a highly reliable database since it could playa crucial role in documenting at real-time basis temporal and spatial changes occurred in the facilities. It is anticipated that this research output will greatly serve to introduce the reliable and cost-effective facility mapping system in the university by overcoming serious constraints suffered from the past non-real time mobile GIS approach.

• Journal of Convergence for Information Technology
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• v.10 no.9
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• pp.251-261
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• 2020

The purpose of this research is to examine the relationship between motivation, reliability, satisfaction, and sustainability of YouTube content and suggest the implications needed for content consumption or production of beauty workers in the future as K-beauty's interest is increasing due to the global Hallyu craze, and beauty industry workers are also watching YouTube hair care content and exchanging the latest trends. The analysis methods included frequency analysis, factor analysis, reliability analysis, correlation analysis, and multi-recovery analysis. As a result, the correlation between the motivation for content use, reliability, satisfaction, and persistence was shown, the motivation for content use was statistically significant (+) and the impact of content reliability on YouTube content satisfaction and sustainability (a significant statistical+).

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.13-13
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• 2014

Two kinds of mushrooms, Gumji (金芝; Ganoderma) and Soji, were described in old book of Samguksagi (History of the three kingdoms; B.C 57~A.D 668; written by Bu Sik Kim in 1145) in Korea-dynasty. Many kinds of mushrooms were also described in more than 17 kinds of old books during Chosun-dynasty (1392~1910) in Korea. Nowadays, mushroom cultivation has been increased through out the world last decade years. Production of mushrooms has also been increased 10-20% and many varieties have been cultivated. Similar trends were also observed in Korea. Approximately two hundred commercial strains of 37 species in mushrooms were developed and distributed to cultivators. Somatic hybrid variety of oyster mushroom 'Wonhyeong-neutari' were developed by protoplast fusion, and distributed to grower in 1989. The fruiting body yield index of somatic hybrids of Pleurotus ranged between 27 and 155 compared to parental values of 100 and 138. In addition, more diverse mushroom varieties such as Phellinus baumi, Auricularia spp., Pleurotus ferulae, Hericium erinaceus, Hypsizigus marmoreus, Grifola frondosa, Agrocybe aegerita and Pleurotus cornucopiae have been attempted to cultivate in small scale cultivation. Production of mushrooms as food was 190,111 metric tons valued at 800 billion Korean Won (one trillion won if include mushroom factory products; 1dollar = 1,040 Won) in 2011. Major cultivated species are Pleurotus ostreatus, Pleurotus eryngii, Flammulina velutipes, Lentinula edodes, Agaricus bisporus, and Ganoderma lucidum, which cover 90% of total production. Since mushroom export was initiated from 1960 to 1980, the export and import of mushrooms have been increased in Korea. Technology developed for liquid spawn production and automatic cultivation systems lead to the reduction of the production cost resulting in the increasement of mushroom export. However some species were imported because of high production cost for these mushrooms requiring the effective cultivation methods. Developing of effective post-harvest system will be also directly related to mushroom export. In academic area, RDA scientists have been conducting mushroom genome projects. One of the main results is the whole genome sequencing of Flammulina velutipes for molecular breeding. An electrophoretic karyotype of of F. velutipes was obtained using CHEF with 7 chromosomes, with a total genome size of approximately 26.7 Mb. The mususcript of the genome of F. velutipes was published in PLOS ONE this year. For medicinal mushrooms, we have been conducting the genome research on Cordyceps and its related species for developing functional foods using this mushroom. In 2013, Korea Food and Drug Administraion (KFDA) approved Cordyceps mushroom for its value as an immune booster.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.284-294
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• 2020

As a solution to local and social problems, the active use of smart city living labs is becoming increasingly important. The answer to solving local and social problems lies in the citizen and the field. The purpose of this study is to establish a smart city living lab model based on citizen participation. In this study, smart city living lab model(4P-SCLLM) based on citizen participation was established through domestic and overseas living lab methodology and case analysis. In order to evaluate the systemicity and specificity of the 4P-SCLLM, a smart city living lab model, we recently compared it with the living lab process in Busan where smart city living lab is applied. As a result of analyzing, the analysis shows similar trends in each stage, and Busan's private sector showed a similar process to 4P-SCLLM On the other hand, public and private sector cooperation and support systems were found to be less than the 4P-SCLLM model And In technology and methodology, the 4P-SCLLM model is analyzed to have a living lab process that incorporates new technologies. In order to maintain the 4P-SCLLM continuously, first, participants and stakeholders need to participate actively and communicate while collaborating on the whole process from start to finish. Second, public awareness needs to be improved. Third, continuous citizenship verification of services is needed. Fourth, citizens' constant participation is needed. Through these implications, this study proposed 4P-SCLLM as a smart city living lab model suitable for the domestic situation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.10
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• pp.855-862
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• 2017

Due to the weight reduction and miniaturization of satellites, there is a growing interest in low-cost launch vehicles, which are cheaper to launch than larger launch vehicles. One of the most cost-effective ways to reduce the cost of launch vehicles is the reuse of vehicles. Most companies that are developing low cost launch vehicles are also adopting a vehicles reuse approach. Along with this reuse purpose, the demand for environmentally friendly space launch vehicles has increased, so the choice of fuel used for low cost launch vehicles has also become very important. Methane and hydrogen-enriched compressed natural gas (HCNG), which makes more energy-efficient by adding hydrogen to methane, are considered to be the most suitable when considering other factors such as energy density among the fuels that are eco-friendly and capable of reusing the launch vehicles. This study investigated the trends of low-cost launch vehicle and rocket fuel in the world as a reference for setting up domestic space development after the development of Korea Space Launch Vehicle-II.