• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.941-946
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• 2023

To improve the lift, cruise speed, and range of eVTOL aircraft, which are being considered as future transportation vehicles, this paper introduces the concepts of Tilt Rotor and Tandem Wing to the aircraft. We developed an aircraft and conducted flight experiments to obtain flight videos and flight logs. The results of the analysis of the flight videos and flight logs showed that the aircraft's moment was excessively forward and the attitude was not recovered. To address this problem, we modified the wing incidence angles and surface areas in XFLR5 to obtain the optimal pitching moment coefficients to ensure vertical stability. We then analyzed the redesigned aircraft, developed using CATIA, through XFLR5. The results of this study provide valuable insights, suggesting that the incorporation of Tilt Rotor and Tandem Wing designs can contribute to achieving stable pitching moment coefficients. This innovative approach offers a promising avenue to significantly enhance vertical stability in UAM vehicles, paving the way for future advancements in the field.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.451-453
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• 2001

제스쳐(gesture)는 마우스 또는 스타일러스의 난일 표시(single mark)를 이용하여 객체들과 기능들을 식별하는 문서 편집 도구의 강력한 방법들 주 하나이다. 마우스를 위한 제스쳐는 주로 데스크 팁 기반의 환경을 위해 개발되어지고 스타일러스를 위한 제스쳐는 보통 휴대용 컴퓨터를 위해 개발되어진다[2]. 현대는 PDA(Personal Digital Assistant)시스템의 스타일러스를 위한 제스쳐 개발이 활발하게 이루어지고 있다.[3]. 하지만 PDA 시스템에서는 인식에 의한 문자 입력의 보조 도구 정도의 수준에서 제스쳐가 사용되어진다. 본 논문에서는 PDA 시스템에서 사용되는 키보드의 키 역할을 하는 기존의 제스쳐와는 달리 사용자 입력과 제스쳐에 차별을 두지 않고 한 화면에서 직접적이 제스쳐가 가능한 환경을 개발하고 다양한 제스쳐 인식 방법을 제안한다. PDA 시스템에서의 제약을 최소화하기 위해 펜 기반의 입력에서 각 스트록을 간략화시켜 정보를 최소호 한 뒤 각 스트록을 양방향 연결 리스트를 이용해 연결하였다. 제스쳐(gesture)는 삽입, 삭제의 기본적인 것들을 비롯하여 이동, 복사, 붙임과 같은 제스쳐도 포함되어 있다. 제스쳐(gesture)의 인식은 각 스트록의 바운딩 박스와 점들의 위치 정보, 스트록 생성 순서에 기반하여 이루어지기 때문에, 이로 인해 펜 기반의문서 에디터 사용에서 요구되는 다른 제약 없이 오로지 펜만으로 모두 편집 환경을 구현할 수 있다.

• Journal of KSNVE
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• v.8 no.3
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• pp.477-484
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• 1998

An analytical procedure on the base of the substructure synthesis and assumed modes method is developed to investigate the flexibility effect of bladed disk assembly on vibrational modes of flexible rotor system. In modeling the system, Coriolis forces, gyroscopic moments, and centrifugal stiffening effects are taken into account. The coupled vibrations between the shaft and bladed disk are then extensively investigated through the numerical simulation of simplified models, with varying the shaft rotational speed and the prewist and stagger angles of the blade. It is found that the Coriolis and inertia forces and the inertia torque, which are induced by the one nodal diameter modes of the bladed disk and vary depending upon the stagger and prewist angles, lead to the coupled motions of the shaft and the bladed disk.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.101-109
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• 1997

An analytical procedure on the base of the substructure synthesis and assumed modes method is developed to investigate the flexibility effect of bladed disk assembly on vibrational modes of flexible rotor system. In modeling the system, Coriolis forces, gyroscopic moments, and centrifugal stiffening effects are taken into account. The coupled vibrations between the shaft and bladed disk are then extensively investigated through the numerical simulation of simplified models, with varying the shaft rotational speed and the pretwist and stagger angles of the blade. It is found that the Coriolis and inertia forces and the inertia torque, which are induced by the one nodal diameter modes of the bladed disk and vary depending upon the stagger and pretwist angles, lead to the coupled motions of the shaft and the bladed disk.

• Journal of Biomedical Engineering Research
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• v.19 no.2
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• pp.129-132
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• 1998

A new one-channel phased-array quadrature RF coil is developed for spine MR imaging. Quadrature RF coils for MRI have been used to improve the signal-to-noise ratio (SNR) by$"\squt{2}"$ using two orthogonal RF coils in combination. More recently, the phased-array RF coil has been proposed for more improvement of SNR by using an array of reduced-size RF coil elements. Two schemes proposed for the new phased-array quadrature RF coil are:(1) Proper overlapping of two quadrature RF coils thus removing the mutual inductance and (2) Attaching preamplifiers right after the coil section and combining the signal with proper phase delays. The coil has been implemented for receive-only mode, and tested by phantom and volunteer imaging. The experimental results show the utility of the proposed RF coil.d RF coil.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.181-186
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• 2001

During the growth of fruit vegetables such as pepper, cucumber and tomato, there are light deficiency under the plant canopy. This study was conducted to clarify the effect of light diffusion film on the stem growth, canopy, flowering and fruiting of green pepper in greenhouse. The transmittance of total solar radiation into greenhouse under woven and double films were 90% and 75% of polyethylene film. And the transmittance of photosynthetically active radiation into greenhouse under woven and double films were 96% and 81% of polyethylene film. However, the light diffusions under woven, double and polyethylene films were 46%, 31% and 9%, respectively. The plant height under polyethylene film covered greenhouse was 96.9% cm, taller than those under woven and double films by 6.5, 13.9 cm. And the third node length under woven film covered greenhouse was 8.6 cm, shorter than those under double and polyethylene films by 2.5, 5.7 cm. Also the first branch angle under woven film covered greenhouse was 61.0$^{\circ}$, larger than those under double and polyethylene films by 2.3, 10.3$^{\circ}$. But there was no clear difference in the node numbers among the covering materials. The rate of curved and sterile fruit under woven film covered greenhouse was smaller than those under double and polyethylene films by 4.6, 5.5% and 1.2, 3.6%. But the contents of vitamin C showed no difference among the covering materials and plant densities.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.2
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• pp.40-47
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• 2009

This paper proposes a method for vehicle license plate detection using mathematical morphology and symmetry. In general, the shape, color, size, and position of license plate are regulated by authorities for a better recognition by human. Among them, the relatively big intensity difference between the letter and the background region of the license plate and the symmetry about the plate are major discriminating factors for the detection. For the first, the opened image is subtracted from the closed image to intensify the region of plate using the rectangular structuring element which has the width of the distance between two characters. Second the subtraction image is average filtered with the mask size of the plate. Third, the column maximum graph of the average filtered image is acquired and the symmetry of the graph is measured at every position. Fourth, the peaks of the average filtered image are searched. Finally, the plate is assumed to be positioned around the one of local maxima nearest to the point of the highest symmetry. About 1,000 images taken by speed regulation camera are used for the experiment. The experimental result shows that the plate detection rate is about 93%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.380-385
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• 1998

This study evaluated the possible utilization and the replacing range of animal by-product mixture (ABPM) as a dietary fish meal replacer in growing common carp (Cyprinus carpio). ABPM is a mixture of leather meal, meat and bone meal, blood meal and squid liver powder at a specific weight based ratio. Five different diets were formulated on isonitrogenous and isocaloric basis of $40\%$ crude protein and 15.3 KJ/g diet in which white fish meal (WFM) protein was substituted with the ABPM Protein as follows: diet 1, $100\%$ WFM ($0\%$ ABPM, control); diet 2, $75\%$ WFM+$25\%$ ABPM ($25\%$ ABPM); diet $3,\;50\%$ WFM+$50\%$ ABPM ($50\%$ ABPM); diet 4 $25\%$ WFM+$75\%$ ABPM ($75\%$ ABPM); diet $5.0\%$ WFM+$100\%$ ABPM ($100\%$ ABPM). As the dietary protein sources, each diet contained $34.7\%$ of animal protein supplied by white fish meal and/or ABPM and $65.3\%$ of plant protein. After one week of conditioning period, fish averaging 10 g were randomly assigned to each diet treatment as triplicate groups and fed one of the experimental diets for 12 weeks. Weight gain of fish fed diet 1 (control) and 3 were significantly higher than those of fish fed diet 2, 4 and 5 during the first 4 weeks (P< 0.05), while there were no significant differences among all diet groups during the third 4 weeks (P>0.05). Feed conversion ratio of fish fed diet 1 was significantly higher than those fed diet 2, 3, 4 and 5 during the second 4 weeks (P<0.05), while there were no significant differences among all diet groups during the first and the third 4 weeks (P<0.05). There were no significant differences in proximate analysis among fish fed the experimental diets either for the second 4 weeks or the third 4 weeks (P>0.05). These results indicated that ABPM could be used as a fish meal replacer up to $100\%$ in growing common carp.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.22-36
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• 2019

This research identified landscape characteristics of Chilitan(칠리탄) area, which had been managed by Son Giyang(1559~1617, p. Ohhan), in order to understand the political viewpoint and ideal landscapes, sought after by Confucian scholars in the 16~17th century. As the research method for the interpretation of each scene's spatial strucutres and meanings, paintings and poems in Chiltanjungsipyukgyeongdo(the Paintings of the 16 Scenes of Chiltanjung Area) were analyzed, which were followed by the on-site survey. Son lived hermit life with the nature after he decided to retire into the country for the chaotic political environment in the 4^th year of Gwanghaegun's reign. Admiring Eum Jareung(B.C. 39-41, p. Eumgwang)'s hermit life, he named a headstream to Chilitan, erected pavilion and made place for angling by the stream, as Eum did in the hermitage. However he worried the king and royal politics in spite of his hermit life, which showed his political viewpoint of Confucianism. In addition, every column of buildings in the garden was named in order to imply both thoughts of Neo-Confucianism and Idleness Naturalism, which highlight a moral training and being comfortable amid poverty and taking pleasure in and honest life style. The present landscape of wonlim could be back to 1936, where Unganru, Byeokripjae and Chiltanjung are surrounding Eupcheondang. Chines character, such as Jimamsuseok, Giam, Ohhansonsunseongjanggujiso and Jogi, are inscribed on the rocks in the landscape garden, from which placeness could be inferred. According to the record of the construction, pine, fir, paulownia, ginkgo, peach trees, bamboo and lotus were planted, and ginkgo, bamboo, crape myrtle, pine and chestnut tress are still living in the garden, which mean plants had been planted in the light of their practical values as well as symbolic meanings. The method for describing 16 scenes of Chiltanjung could be characterized to the structure of 「Place+Scene(a particural activity, event, or action), and these placeness could be analyzed by categorizing the scene to near, middle and far views. Each scene symbolically presents a hermit, noble man, Taoist ideology, homeland, or peacetime, which were adpoted to depict landscapes of Chiltanjung area as the Confucian utopia.

• Korean Journal of Heritage: History & Science
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• v.38
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• pp.5-42
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• 2005

Based on a field investigation of intangible cultural asset # 2, author Sir Shin Seok-bong of Daejeon Metropolitan Cityinvestigated the music of Antaek-gut, which is the base and core of Anjoon-gut, and found the following musical features: A Jang-gu(drum) and Kkoaengkwari(gong) were used to recitethe Sutra(kyungmoon) of Anjoon-gut. The Jang-gu, located on the right side, played an accompaniment role with regular beats when the Sutra was recited. The Kkoaengkwari, located on the left side, played the role of covering the caesura of the Sutra passages, so it is played with various rhythmic variations in accordance with Kojang(鼓杖). This is one way of playing Korean national classical music that has temporary caesuras, depending on the rector's bre! ath or the contents of a Sutra during the Sutra chanting, with the Jang-gu covering the pause with its variation. In other words, when being played in concert, the instruments that play the main melody are at rest while another instrument takes its turn to play the main melody as a form of prolonged sound. The rhythmic cycles of the sutras of Antaek-gut recited with this instrumental accompaniment consist of five types; a) Woemarch-jangdan (a single beat) of 4 meter by 3 bit, b) Dumarch-jangdan (two beats) of 8 meter by 3 bit, c) Saemarch-jangdan (three beats) of 4 meter by 3 bit with a fast tempo, d) Mak-gojang, uniform beats with a standardized rhythm, and e) incomplete beats deviated from the regular beats. Sir Shin Seok-bong chanted Chang (唱), a traditional native song which he called 'Cheong (淸)' with a cycle of 'Dumarch-jangdan' throughout the places of Antaek-gut. Only 'Toesonggyung' a chant for the gate that was the last location of the Antaek, was chanted with a cycle of 'Woemarch-jan! gdan'. In addition, 'Saemarch-jangdan' and 'Mak-gojang' that had comparatively faster tempos than the former two jangdans, were played without a chant when a female shaman was dancing and catching her spirit-invoking wand. The 'Saemarch-jangdan', particularly, was played while dancing began at a relatively slow tempo, then proceeded at a violent tempo and then back again to the slow tempo. This shows one of the representative tempos of our music with a slow-fast-slow tempo. The organizational tones were 'mi-la-do'-re'', and its key tones of 'mi-la-do'' were performed with perfect fourth and minor third, which was the same as those of Menari-tori. However, it did not show a typical Sigimse, an ornamental tone, of Menari-tory, whose first tone, 'mi', is vibrated and its Sigimse is gliding down from the tone 're' to 'do'. That is because the regional tone-tori of Chungcheong-do have a relatively weaker musical expression than that of Gyeongsang-do. In addition, the rhythmic types in accordance with the words of a song for the Antaek-gut music had a comparatively faster tempo than the other sutras. Also, it was only with 'Toesonggyeong' that the tone 'la' continuously appeared throughout the melody and showed 'a syllabic rhythm', while other places consisted of either a 'syncopation' or 'melismatic' rhythm. Finally, according to a brief investigation of the tone organization in accordance with each sutra, the tone 'la' was given more weight. The tone procedure showed a mainly ascending 'la-do'' and the descending 'la-mi' with minor third and perfect fourth. Also, the overall tempo proceeded with M.M.♩.=116-184, while the tempo for the Gut proceeded with M.M.♩.=120-140, which was suitable for reciting a Sutra.