• Journal of the Korean Society for Aviation and Aeronautics
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• 제14권4호
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• pp.110-119
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• 2006

This research was conducted with a view to enhance the efficiency of the preventive tool which provide pilots and controllers with proper and timely safety alerts while conducting circling approach at the airport where surrounding terrains becomes threat to safe operation of flight around airport.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제32권4호
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• pp.45-52
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• 2009

The objective of this was to improve a transportation cost relation between Central Distribution Centers(CDCs) and Regional Distribution Centers(RDCs), to control inventory cost concerning safety stock for each service level, by reviewing distribution steps connecting CDCs and RDCs under the price discount. It was also to examine and compare operating costs for the following two alternative suggestions for setting the service standard as a counter measure for a stock-out of the distribution network system management. First, provision by dispersing the safety stock to the CDCs and RDCs; and second, exclusive provision of the safety stock only to the RDCs. The cost comparison analysis was made for each category of purchase costs, regular transportation costs, express transportation costs, and inventory holding costs.

• Journal of the Korean Society for Aviation and Aeronautics
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• 제28권4호
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• pp.55-62
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• 2020

Special airworthiness certificates can be issued if the aircraft does not meet the airworthiness standards, but it is deemed that it can be operated safely by partially limiting the scope of operation and flight performance. Currently, Korea is subject to experimental special certification for UAS(Unmanned Aircraft Systems) exceeding 150 kg of its own weight, but detailed guidelines need to be prepared on how to prove that they can be operated safely in a limited range. Recently, Korea Airworthiness Standard(KAS) Part 21 has been revised to reflect this, but it needs to be supplemented. In this study, through an understanding and analysis of the FAA's procedure of expeirmental special airworthiness certifications for UAS, we would like to suggest what we should consider when developing relevant guidelines in our country.

• Journal of Korean Society for Geospatial Information Science
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• 제22권4호
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• pp.21-30
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• 2014

Lately, new influentials have secured a large number of volunteers on social networks due to vitalization of various social media. There has been considerable research on these influential people in social networks but the research has limitations on location information of Location Based Social Network Service(LBSNS). Therefore, the purpose of this study is to propose a spatial detection methodology and application plan for influentials who make comments about diverse social and cultural issues in LBSNS using spatial statistical analysis methods. Twitter was used to collect analysis object data and 168,040 Twitter messages were collected in Seoul over a month-long period. In addition, 'politics,' 'economy,' and 'IT' were set as categories and hot issue keywords as given categories. Therefore, it was possible to come up with an exposure index for searching influentials in respect to hot issue keywords, and exposure index by administrative units of Seoul was calculated through a spatial joint operation. Moreover, an influential index that considers the spatial dependence of the exposure index was drawn to extract information on the influential areas at the top 5% of the influential index and analyze the spatial distribution characteristics and spatial correlation. The experimental results demonstrated that spatial correlation coefficient was relatively high at more than 0.3 in same categories, and correlation coefficient between politics category and economy category was also more than 0.3. On the other hand, correlation coefficient between politics category and IT category was very low at 0.18, and between economy category and IT category was also very weak at 0.15. This study has a significance for materialization of influentials from spatial information perspective, and can be usefully utilized in the field of gCRM in the future.

• Journal of Korea Society of Industrial Information Systems
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• 제20권3호
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• pp.37-49
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• 2015

To develop the contents making profit, we propose the program operation methods that can apply the needs of students and the demand of the times, and consider the capacity of the operating agency overall. First, we suggest the distance training motivation, the effective content type, appropriate interaction ratio, the effective teaching and learning methods and the assessment methods. Second, we suggest the development strategy of educational contents, assess quantitative the demand of students and the will of teacher overall, measure the potential success. Third by applying the strategies in the educational field, we product the 12 major development field. These fields are divided into categories A and B, category A is the very high success field and category B is the high potential success field. By applying the proposed strategy, You will select the most suitable contents here and now.

• Journal of Society of Preventive Korean Medicine
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• 제21권1호
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• pp.95-106
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• 2017

Objectives : Although interest in preventive medicine has increased recently, "Mibyeong", the preventive concept of Korean medicine, is still unfamiliar to the general public. Therefore, this study aims to investigate the concept of Mibyeong and users used on the Internet. Methods : Naver (www.naver.com), which has the highest ranking in terms of market share, number of visitors, search time share, and community category share, has been selected as a search target and jisik-iN Q&A and posts of cafe about Mibyeong were searched for recently approximately 6 years. Results : 105 cases of Jisik-iN Q&A and 283 cases of cafe posts were searched. Overall, the number of Jisik-iN Q&A and cafe posts's Mibyeong term usage was the highest in 2013. In the Internet user category, Mibyeong Term was used most commonly in the Jisik-iN Q&A by Korean medicine related medical personnel (29 cases, 28%) and in the cafe other health-related workers (87cases, 31%). In Mibyeong related cafe classification, Information Exchange (220 cases, 77%) was the most frequent and besides 39 cases (14%) used in Operation of Medical Institutions. And the concept of Mibyeong was often used as symptom-based rather than diagnostic test or disease (Cafe posts 52%, Jisik-iN Q&A 70%), in particular, topic of Mibyeong related Jisik-iN Q&A was used in the order of pain (31 cases, 16%), cancer (17 cases, 9%), fatigue (11 cases, 6%). Conclusions : This study has significance as basic research data of general Internet user group and can be used as fundamental data for awareness promotion, publicity and necessity of Mibyeong.

• Safety and Health at Work
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• 제1권2호
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• pp.192-200
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• 2010

Objectives: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane. Methods: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). Results: Acutely-exposed rats became lethargic but recovered following discontinuation of inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute inhalation toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was 'not grouping'. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ toxicity upon repeated exposure. Conclusion: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent inhalation-related adverse health effects of workers.

• Journal of Environmental Impact Assessment
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• 제21권1호
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• pp.15-24
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• 2012

The purpose of this study is to understand the process and characteristics of social impact caused by development projects through research and analysis on issues presented during development projects carried out in Korea. Furthermore, on the basis this analysis, this study proposes possible improvement measure environmental impact assessment for minimizing social impact of development projects in the future. Issues related to development projects are generated mainly by the following three causes. Initial social impact can occur when a development project directly causes certain changes in natural, living and social environment. Operational problems related to assessment are another cause of social impact, and it can also occur when changes in natural and living environment work in tandem with social environment sphere. Social impact of development projects is not brought about solely by changes in social environment, but is the result of interaction of factors such as changes in social, natural, living environment and problems related to assessment or operation/management. As to why the current environmental impact assessment could not provide satisfactory solution to the issues mentioned above, this study suggests the following reasons: limitations of assessment method used in social environment category, difficulties in defining assessment criteria, limitations inherent in criterion referenced assessment method, insufficient issue-making in local community, and lack of participation on the part of local residents. Possible solutions for these limitations are as follows: 1) To identify local issues in social environment category through participation of local experts in scoping stage, 2) To adopt deliberative method for local participation, 3) To utilize social survey technique.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.209-211
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• 2022

YouTube, a video platform used by millions of people worldwide, provides a rapidly growing video service. This study aims to understand the characteristics and cultural differences of each country using the Kaggle dataset, one of the public datasets, and to show the usefulness of the public dataset. For this purpose, we analyze data from 11 countries, 15 categories, and about 1.1 million trending videos. This study adopts Python to obtain the number of videos by category for data analysis, the selection period of videos rapidly increasing in popularity, and the ratio of unique videos. In the future, based on machine learning, we plan to research to help diagnose individual videos and establish channel operation plans and strategies by predicting the selection possibility and selection period based on machine learning.

• Transactions of the Korean hydrogen and new energy society
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• 제29권1호
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• pp.111-116
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• 2018

The environmental impacts of a 1 kW polymer electrolyte membrane fuel cell (PEMFC) system are quantitatively assessed by performing a Life Cycle Assessment (LCA) study. A PEMFC system produces electricity and heat simultaneously, so an appropriate allocation of associated inputs and outputs is performed between the electricity and heat produced. The environmental impacts of the PEMFC system on the impact categories such as global warming (GW), abiotic depletion (AD), acidification (AC), and eutrophication (EU) are assessed from the life cycle impact assessment. The impact indicator results of the impact assessment on these impact categories are obtained as $3.70E-01kg\;CO_2\;eq./kWh$, 1.86E-03 kg Sb eq./kWh, $4.09E-04kg\;SO_2\;eq./kWh$, and $1.88E-05kg\;PO_4{^{3-}}/kWh$, respectively. For all impact categories studied the most influential stage is the operation stage, which accounts for 98.8%, 98.7%, 70.3%, and 62.3% of the total impact on GW, AD, AC, and EU, respectively. For the impact categories of AD, AC, and EU, most of the environmental impacts during the operation stage is attributed to the production of city gas. However, for the impact category of GW, $CO_2$ emission from the reforming process of city gas is the main reason for the largest contribution of the operation stage to the total impact results.