• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.3
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• pp.1-17
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• 2023

Korea's natural parks are managed by dividing them into four use districts: nature preservation district, natural environment district, cultural heritage district, and park village district within the park under the goal of 'conservation and sustainable use of natural parks'. However, the use districts divided in this way are designated by reflecting the results derived from the simple drawing overlapping method, and there is a limit in that objective and scientific evidence for this is insufficient. In addition, in Taeanhaean National Park, the case of this study, only a very small area of less than 1% of the nature preservation district is designated, and the natural environment district that serves as a buffer space is designated on an excessively wide scale, making it difficult to efficiently manage the national park. Therefore, the use district is not fulfilling its role. In this study, the purpose of this study was to present a method for analyzing the spatial characteristics of natural parks using environmental indicators and unsupervised learning analysis methods to set the use districts of natural parks. In this study, evaluation indicators that can evaluate the natural and human environments were derived, and the distribution patterns for each indicator were analyzed. Afterwards, by applying Self-Organizing Map (SOM) analysis, one of the unsupervised learning analysis methods, districts with similar characteristics were derived in Taeanhaean National Park, and the characteristics of each district were analyzed. As a result of the study, 7 districts with different characteristics were derived in Taeanhaean National Park, and by examining the contribution of each indicator together, it was possible to reveal that each district had different representative characteristics even though it was an adjacent area. This study evaluated natural parks by comprehensively considering the indicators of the natural and human environments. In addition, the SOM method used in the study is meaningful in that it can provide scientific and objective grounds for the existing zoning and apply it to the management plan.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.3
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• pp.13-20
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• 2009

Development of a dynamic engine model is essential to predict and analyze of dynamic characteristics from a natural gas engine. Reducing the harmful exhaust emissions can be accomplished by a precise air-fuel ratio control. In this paper, the dynamic engine model was proposed and included mixture formation and intake process because the dynamic characteristics can be affected by the mixture components such as an air and a gaseous fuel. The air mass flow, the partial pressure ratio, and the gas constant are changed by variations of the components in the mixture formation and intake process. The dynamic engine model is applied to the natural gas engine for validation test. Experimental results show that the dynamic engine model is effective to predict the dynamic characteristics of the natural gas engine.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.148-154
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• 2004

As a rocket propellent of hydrocarbon fuels, the characteristics of liquefied natural gas was evaluated with the viewpoint of the constituents and content, the cooling performance as a coolant, and characteristic velocity and specific impulse as parameters of the engine performance. Content of methane was a principal factor to determine the characteristics as a rocket propellant and more than 90 % of it was needed as a fuel and coolant in the regenerative cooled liquid rocket engine. Some constituents of the liquefied natural gas can be frozen by the pre-cooling of the pipe lines, therefore they can be a factor disturbing the normal working of engine. In case the content of methane is around 90% in the liquefied natural gas, a normalized stoichiometric O/F mixture ratio of 0.75 is suggested for a nominal operation condition to get the maximum specific impulse and characteristic velocity.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.99-104
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• 2008

The Carbon fiber epoxy composite material and aluminum have many advantages about higher specific stiffness and good fatigue characteristics. basically, the propeller shaft of automobile must satisfy high natural frequency more than 9,200 rpm to satisfy high number of rotation and high torsion torque more than 2,700Nm. In these reason, studied natural frequency and torsion torque characteristics of shaft according to parameter variations with the outdiameter and thickness. From the torsion tester and natural frequency experiments FE analyses was compared vibration and torque characteristics of hybrid shaft Designed hybrid shaft was experimented through FFT analyzer and torsion tester each and satisfied that hybrid shaft reverence 60mm and thickness 5mm by a these experiment is most suitable. Therefore, that can manufacture existent steel two piece type propeller shaft to one piece type hybrid shaft.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.5
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• pp.804-816
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• 2009

This study was aimed to analyze color characteristics of silk fabrics dyed with a variety of commercial natural dyes focusing on hue/tone system. Using eleven different natural dyes, single and sequential dyeing were performed under a variety of conditions of dye bath concentration, mordanting, and dyeing sequences. Color characteristics of dyed silk fabrics were investigated by Munsell's color notation of H V/C and PCCS (Practical Color Coordination System) tones. As results, most of yellowish natural dyes as principal shades in natural dyeing showed Y or YR for hue families while d, ltg, and g for tone, which agrees with colors frequently used in comtemporary apparel industries. As for single dyeing, some hues like R, RP, G, GY, and BG were found to have their own tones owing to the used natural dyes. For varying hues in natural dyeing, sequential dyeing is useful in that GY, G, and BG rarely appeared in single dyeing were frequently shown in sequential dyeing by combination of some dyes. In the other hands, mordanting may be employed for tone variation in that aluminum seemed to contribute to light and dull tones, copper to dull, and ferrum to garyish and dark ones. These results can be helpful to design colors for fashion fields by natural dyeing.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.1
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• pp.79-86
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• 2009

This paper proposed an algorithm for extracting spectrum gradient parameter to analyze the characteristics of natural seismic sounds and artificial seismic sounds. The experiment was performed in various area to raise the reliability. The characteristics of natural seismic sounds and artificial seismic sounds were analyzed by extracting gradient indexes of artificial seismic sounds and natural seismic sounds from the data of experiment by using the proposed algorithm. As a result of the experiment and the analysis, gradient indexes of natural seismic sounds were higher than that of artificial seismic sounds because natural seismic sounds had higher attenuation at high-frequency than artificial seismic sounds did and natural seismic sounds were concentrated in low-frequency band.

• Journal of the Speleological Society of Korea
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• no.85
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• pp.18-20
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• 2008

To find out the natural environmental characteristics of Ondal Cave, temperature, humidity, wind speed and water temperature have been investigated. When compared to other caves, in sum, Ondal Cave has shown no significant difference interms of natural environment. Inparticular, Ondal Cave was higher than other limestone caves by 1-2$^{\circ}C$ in terms of water temperature due to high inflow of river water nearby.

• Journal of the Korean Society of Earth Science Education
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• v.1 no.1
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• pp.41-51
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• 2008

For teaching-learning to geological region of earth science part in science education, middle school, the practical uses of natural science museum are very effective. So, the appropriate uses of the natural science museum are necessary for the teaching and learning of Science Education. This study aims to consider the presentation characteristics of the natural science museum and to examine how is effective it to geological region in middle school science curricula on those uses. From the results, the natural science museum is low in multi-sided and open-endedness presentation characteristics but high in ones of accessible characteristic. And its presentations are good in multimodal characteristics using supported materials but relatively low in relevant and multimedia ones. In the museum, diorama and self-performing presentation types are not but internet ones are most. The presentations of the natural science museum are mainly assigned to knowledge region linked to basic science concepts but relatively insufficient in STS aspects, on the basis of connection the presentations with middle school science curricula. It is respected that these insufficiencies might be diminished by variable arrangements of and explanations to the presentations for understanding improvements. And, applies to the presentations in STS may be encountered, if multi-sided observations to them is available.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.319-322
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• 2007

This study aims to find the characteristics of damage and states of natural disasters at the Korean Peninsula from 1985 to 2004. Using the data of Statistical yearbook of calamities issued by the National Emergency Management Agency and Annual Climatological Report issued by the Korea Meteorological Administration. we have analyzed the cause, elements, and vulnerable regions for natural disasters. Major causes of natural disaster at Korean Peninsula are four, such as a heavy rain, heavy rain typhoon, typhoon, storm snow, and storm. The frequency of natural disaster is the highest from June to September. The period from December to March also shows high frequency. The total amount of damage is high during the summer season(Jul.-Sept). The period from January to March shows relatively high amount of damage due to storm and storm snow The areas of Gangwon-do, Gyeongsangnam-do and Gyeongsangbuk-do are classified the vulnerable region for the natural disasters. By establishing mitigation plans which fit the type and characteristics of disaster for each region, damage from disaster can be reduced with efficient prevention activities.

• Journal of the Korean Home Economics Association
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• v.40 no.9
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• pp.191-205
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• 2002

The purpose of this study is to identify the homelike design characteristics of elderly housing facility. To investigate what the preference of physical design characteristics are, interview was done by unstructured questionnaire to 30 middle aged and middle income group housewives living in Seoul. It was identified that preferred homelike physical characteristics of the houses were composed of 4 themes, housing types, building appearences and garden, floor plan and natural and social environments of its location. Their desirable housing standard was amenity which is the highest level of home environment. In their later life, they wanted to live in vicinity of Seoul to enjoy cultural benefits of the city and active outdoor activities in sunny, natural suburban environment. They liked a spacious, clean and bright color with natural material furnishings. Each architectural design expression of 4 themes was suggested.