• Journal of Korean Society for Geospatial Information Science
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• v.22 no.1
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• pp.81-88
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• 2014

The researcher of this study applied PCA on aerial hyper-spectral sensor and selectively combined bands which contain high amount of information, creating five types of PCA images. By applying Spectral Angle Mapping-supervised classification technique on each type of image, classification process was carried out and accuracy was evaluated. The test result showed that the amount of information contained in the first band of PCA-transformation image was 76.74% and the second accumulated band contained 98.40%, suggesting that most of information were contained in the first and the second PCA components. Quantitative classification accuracy evaluation of each type of image showed that total accuracy, producer's accuracy and user's accuracy had similar patterns. What drew the researcher's attention was the fact that the first and the second bands of the PCA-transformation image had the highest accuracy according to the classification accuracy although it was believed that more than four bands of PCA-transformation image should be contained in order to secure accuracy when doing the qualitative classification accuracy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.5
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• pp.511-517
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• 2009

A servo type angle of attack sensor using the null-seeking method is designed and its characteristics are analyzed in this study. Angle-of-attack in the null-seeking method is given by the probe rotation angle with respect to the body reference line when pressure difference measured in two holes on the probe becomes zero. This method provides highly accurate and uniform angle-of-attack measurements over all range. Hence, this kind of angle-of-attack sensor is adequate for unmanned aerial vehicles(UAVs). In this paper, we first analyze the requirements for developing angle-of-attack sensors. And the servo type angle-of-attack sensor is then designed and fabricated. The on-board angle-of-attack calculation algorithm is also developed. Finally, the characteristics of the developed angle-of-attack sensor are identified through MATLAB Simulink and wind tunnel tests.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.219-224
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• 2005

In order to investigate transient behaviour of the CRW(Canard Rotor Wing) type UAV(Uninhabited Aerial Vehicle) propulsion system during flight mode transition considering flow control valve operation, the propulsion system was modelled using SIMULINK commercial program. For transient simulation of the main engine system, the ICV(Inter-Component Volume) method was applied. The valve system is to control the gas flow of the rotary duct system and the main duct system, and the analysis was performed with an assumption that the total gas mass flow of the main engine is the same as summation of the rotary duct flow and the main duct flow, and with consideration of valve loss, flow rate and effective area in valve angle variation. The performance analysis was carried out during flight mode transitions from the rotary flight mode to the fixed wing flight mode and vice versa mode at altitude of 1Km, flight Mach number 0.1 and maximum engine rpm.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.103-114
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• 2014

This study intends to make a proposal the direction classification to develop the independent study of e-book's visualization. For this, we research into the e-book of Disney animation which achieved recognition in the literary value and amusement First of all, We grasp the meaning of the concept of e-book's aerial-image and perceptual principle. Next, We found the subject that starts the movement, and then observed the factor of the presentation to be possible to experience the actual spatial experience by the motion-produced cues. Through analysis process, We can classify the appearance elements, media, camera, and the readers' motion-produced cues into 13 parts and define as the codes. As we analysis the frequency of use of the analysis object, We separated it into the 46 combination exercises. According to the combination with the independent exercise, We separated them into 4 groups. There are the actual spatial experience, narrative spatial experience, the experience of characters. The basis for these, we can analyze the characteristics of the motion-produced cues. This study has the meaning of the expansion of e-book into the film language system by separating the e-book's narrative visualization type.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.1
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• pp.47-58
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• 2014

In this research, the initial sizing of a HALE(High Altitude Long Endurance) UAV which uses solar power and hydrogen fuel cell as an alternative energy was performed. Instead of a wing box type, a glider type was chosen since it is relatively easy to get a data thanks to many researches abroad. Maximum takeoff weight is around 150Kg and the propulsion system is composed of motor, propeller, solar cell, and hydrogen fuel cell which can be recharged through electrolysis. Maximum takeoff weight was estimated as aspect ratio, wing span, wing area change while considering energy balance of required energy which is necessary for flight during the entire day and available energy which can be taken from the solar cell.

• Korean Journal of Microbiology
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• v.32 no.1
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• pp.70-77
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• 1994

The author isolated 7 mutant candidates which mapped around cysA (which was 10 o'clock). They were divided into two groups. One of them was located counterclockwise to cysA, and the other was clockwise to cysA. Since bldA was mapped counterclockwise to cysA, the candidate which mapped counterclockwise to cysA was transduced with phage containing wild type bldA gene clone. The candidates might be the alleles of bldA, because they were complemented by bldA clone. However some of such mutants sporulated very well and developed as much pigment as wild type on rich media plate. Their phenotype was not like bld mutant at all on such conditions. There were real antibiotics gene expressions, since transcriptional reporter gene xylE had shown high activities. Majority of the bldA like mutants showed act gene expressions when they were transformed with high copy number plasmid containing actII-ORF4.

• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.224-233
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• 2010

As urban function has become diversified and complicated, multifunctional complex facilities to satisfy new functional desires are necessary. Since local autonomy started, many facilities previously run and managed by central administrative agencies are now under management of localities, and functionally, the necessity for governments complexes town to satisfy diverse taste of populace such as creating local community becomes imminent. Analyzing characteristics by space composition factor of the public health center, newly built as part of such governments complexes town and understanding required area of each part, this project is to be used as basic material for construction plan of public health center that is equipped with local characters while devising construction of the public health center in the governments complexes town. Research method is to analyze four public health center facilities located in governments complexes town sites built after 2007, among twenty five public health centers in Seoul, by spatial functions. Also, based on statistical documents of usage of public health center facilities, research over spatial compositional factors and area composition has been conducted. As a result, connectivity between local government building located inside the governments complexes town and public health center and that of spatial composition factor by part, area ratio by part and floor type of public health center are comprehended. Connectivity type of public health centers are divided into horizontal and vertical connectivity and it is found that spatial composition of public health center is compartmentalized into low level, mid level and high level, to make access by users easier. Level type is decided as radial, rotational and combined by hallway connecting facilities.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2786-2790
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• 2010

Three new oleanane-type triterpene saponins (1, 2 and 3) were isolated from aerial parts of Gladiolus gandavensis, along with two known compounds (4 and 5). Their structures were elucidated as 29-O-($\beta$-D-glucopyranosyl)-$2{\beta}$,$3{\beta}$-dihydroxyolean-12-en-28-oicacid(1), 3-O-($\beta$-D-xylopyranosyl)-29-O-($\beta$-D-glucopyranosyl)-12-en-28-oic acid (2), and $2{\beta}$,$3{\beta}$,29-trihydroxyolean-12-en-28-oic acid 28-O-[$\beta$-D-glucopyranosyl($1{\rightarrow}2$)-($\alpha$-L-rhamnopyranosyl($1{\rightarrow}6$))-$\beta$-D-glucopyranosyl] ester (3), by spectroscopic methods, and by comparison with known analogues. These oleanane-type triterpene saponins glycosidated at C-29 were not obtained frequently.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.127-132
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• 2005

In order to investigate transient behavior, of the CRW(Canard Rotor Wing) type UAV(Uninhabited Aerial Vehicle) propulsion system during flight mode transition considering flow control valve operation, the propulsion system was modelled using SIMULINK commercial program. The valve system is to control the gas flow of the rotary duct system and the main duct system, and the analysis was performed with an assumption that the total gas mass flow of the main engine is the same as summation of the rotary duct flow and the main duct flow, and with consideration of valve loss, flow rate and effective area in valve angle variation. The performance analysis was carried out during flight mode transitions from the rotary flight mode to the fixed wing flight mode and vice versa mode at altitude of 1km, flight Mach number 0.1 and maximum engine rpm.

• Journal of Environmental Science International
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• v.31 no.9
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• pp.735-741
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• 2022

Global warming affects forests and their ecology. Diversity in the forest is a buffer that reduces the damage due to global warming. Mixed forests are ecologically more valuable as versatile habitats and are effective in preventing landslides. In Korea, most forests were created by simple afforestation with trees of evergreen species. Typically, evergreen trees are shallow-rooted, and deciduous trees are deep-rooted. Mixed forest tree roots grip the soil effectively, which reduces the occurrence of landslides. Therefore, improving the distribution of tree types is essential to reduce damage due to global warming. For this improvement, the investigation of tree types of the forest is needed. However, determining the tree type distribution of forests that are spread over wide areas is labor-intensive and time-consuming. This study suggests effective methods for determining the distribution of tree types in a forest that is spread across a relatively wide area. Using normalized difference vegetation index and RGB images from unmanned aerial vehicles, each evergreen and deciduous tree, and grassland area can be distinguished. The distinguished image determines the distribution of tree type. This method is effective compared to directly determining the tree type distribution in the forest by the use of manpower. The data from these methods could be applied to plan a mixed forest or to prepare for future damage due to global warming.