• Title/Summary/Keyword: Wings

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Effects of Strake Planform on the Vortex Flow of a Double-Delta Wing (이중 삼각날개의 와류에 미치는 스트레이크 평면형상의 영향)

  • 손명환;정형석
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.8
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    • pp.16-23
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    • 2006
  • The effects of strake planform shapes on the vortex formation, interaction, and breakdown characteristics of double-delta wings were investigated through pressure measurements of upper wing surface and off-surface flow visualization. Three different shapes of strakes were attached to a delta wing respectively to form double-delta wing configurations and tested in a medium-sized subsonic wind tunnel. The results of the pressure measurements indicated that the strake planform having a higher sweep angle generated more concentrated vortex systems at upstream locations, which, however, tended to diffuse and break down much faster at the downstream locations. It was also found from the off-surface visualization results that the cause for the vortex concentration was due to the acceleration of coiling and merging processes between the wing and strake vortices.

Analytical Parametric Study on Pullout Capacity of Embedded Suction Anchors (매입된 석션앵커의 인발력에 대한 분석적 매개변수의 연구)

  • Boonyong, Sorrawas;Park, Ki Chul;Kim, In Chul
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.3
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    • pp.182-189
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    • 2015
  • The Embedded Suction Anchor (ESA) is a type of permanent offshore foundation that is installed by a suction pile. To increase the loading capacity against pullout, three wings (vertical flanges) are attached along the circumference at 120 degrees apart. Analytical parametric study using the proposed analytical solution method has been conducted to identify the effects of several parameters that are thought to influence the behavior of ESAs. The analysis results show that the pullout capacity increases as the anchor depth and the soil strength increase, and decreases as the load inclination angle increases. The anchor having square projectional area and being pulled horizontally at the middle of its length provides the highest pullout capacity.

Estimation of Aircraft Stability Derivatives Using a Subsonic-supersonic Panel Method (아음속 초음속 패널법을 이용한 항공기 안정성 미계수 예측)

  • Gong, Hyo-Joon;Lee, Hyung-Ro;Kim, Beom-Soo;Lee, Seung-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.5
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    • pp.385-394
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    • 2012
  • A computer program that can estimate static, dynamic stability and control derivatives using a subsonic-supersonic panel method is developed. The panel method uses subsonic-supersonic source and elementary horse shoe vortex distributions, and their strengths are determined by solving the boundary condition approximated with a thin body assumption. In addition, quasi-steady analysis on the body fixed coordinate system allows the estimation of damping coefficients of aircraft 3 axes. The code is validated by comparing the neutral point, roll and pitch damping of delta wings with published analysis results. Finally, the static, dynamic stability and control derivatives of F-18 are compared with experimental data as well as other numerical results to show the accuracy and the usefulness of the code.

The Influences of Flapper Fashion on Modern Fashion (플래퍼 패션이 현대(現代) 패션에 미친 영향(影響))

  • Park, Hye-Won;Cho, Kyu-Hwa
    • Journal of Fashion Business
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    • v.2 no.3
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    • pp.55-72
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    • 1998
  • The purpose of this study is for consideration of the flapper fashion (1924-1928) in Jazz Age (1919-1929) of America and the influences of it on modern fashion. This study is started from the latest fashion trend which is pursuing it's inspiration into the Jazz Age, the 20s. The etimology of 'flapper' was based on mines is 'flap' such as 'flutter of skirt hemline', 'hands', 'arms', 'wings' and a slang which was applied to young women from 1830. In 20th century it has meant not only new American women but also their fashion and attitude. The designs of flapper fashion were expressed by simplicity, functionality, nudity and rhythm. Simplicity was the best value of this time and the simple image was considered the smartest. Functionality was represented by straight boyish style and loose baggy silhouette that was related to free dome. Nudity was expressed by revealing of legs, arms, backs in shapes and see-through by materials. It was related to sexual attraction and point to youth. Rhythm of flapper fashion expressed optical effect of movement. Using of light material was deep related to freedom of flappers, speed, rhythmical Jazz and dancing. The influences of flapper fashion were giving an opportunity that changed fashion leader from high class to young popular group and simple design of flapper fashion effected to modernization and popularization of American apparel business. And it influenced American casual fashion which was known as brightness, youth and openhearted mood. So flapper fashion can be reganded as the starting point of the street fashion of the 20th century.

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Comparative studies on the Hanabusaya asiatica and its allied groups 1. External morphology and anatomical characters (금강초롱꽃 (Hanabusaya asiatica)과 근연분류군의 비교연구 1. 외부형태 및 해부학적 형질)

  • 유기억
    • Korean Journal of Plant Resources
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    • v.8 no.3
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    • pp.223-235
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    • 1995
  • Comparative studies on external morphology and anatomical characters were conducted understand the interspecific relationships and possibly to identify the position of Hanabusaya asiatica as an endemic genus among 4 genera and 9 species in H. asiatica and its allied groups. Such morphological characteristics as root shape, leaf size, presence or absence of wings in petiole, corolla and calyx shape, and inflorescence and stigma shape were useful qualitative characters. The morphology of stem, peduncle, calyx lobe, leaf, petiole, and ovary were also good characters to be included in this identification study. In the anatomical observations in these organs, projecting degree of epidermis and number of projecting area rather than cross-sectioned internal structures were found to be valuable index for the classification among species. External morphology and anatomical characters support the position of H. asiatica as an endemic genus very well. Known as the most important external characters to taxonomists(Fedorov, 1957: Nakai, 1952: Hong, 1983), leaf arrangement, inflorescence, and corolla shape were also preven to be very useful characters to identify the genera and species in the H. asiatica and its allied groups.

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Study on the Manufacturing Technique of Steel-Plated Jewel Beetle's Adornment and Gilt-bronze Openwork Remains (철지비단벌레장식금동투조유물의 제작기법에 관한 연구)

  • Yong, Byoung-Ju;Kang, Jung-Moo;Kim, Soo-Ki
    • Journal of Conservation Science
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    • v.26 no.4
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    • pp.417-427
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    • 2010
  • This study is to examine the manufacturing technique based on scientific investigation and analysis on Steel-Plated Jewel Beetle's Adornment gilt-bronze openwork remains excavated from No. 100 site at Hwango-dong Gyeongju. As a result of the investigation on the manufacturing revealed that riveting was adopted to connect gilt-bronze openwork plates and steel plates, followed by mercury amalgam plating method and carving of the patterns by means of the dotted line engraving technique. There were some traces on the surface of Jewel Beetle wings that show the use of pins for fixing, which seems to be the result of recycling or processing. The sectional analysis shows the high possibilities that varnishing with lacquer was adopted for wing adhesion, and it was confirmed that varnishing with lacquer was used on the strap pendant plate to prevent corrosion.

Courtship Behavior of the Sweet Potato Leaf Worm, Aedia leucomelas (Lepidoptera: Noctuidae)

  • Choi, Man-Young;Kim, Du-Ho;Paik, Chae-Hoon;Seo, Hong-Yul;Kim, Jae-Duk;Lee, Geon-Hwi;Gries Gerhard;Roitberg Bernard D.
    • Korean journal of applied entomology
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    • v.44 no.4 s.141
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    • pp.341-344
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    • 2005
  • Courtship behavior of the sweet potato leaf worm, Aedia leucomelas L. (Lepidoptera: Noctuidae) was observed under laboratory condition. Behavior of antennal Probing and wing fanning in presence of opposite sex was observed in dark room. Both male and female exhibited similar behavior, fanning wing and raising antenna before male flew toward female. Some of moths began raising antenna 20 minutes into scotophase, and 20 minutes later both sexes started to exhibit spectacular behavior, fanning the wings intermittently in high frequency as if producing sound for attracting opposite sexes. They began mating about one day after emergence and mating activity was peaked from 4 to 6 days after emergence. Multiple mating was observed and the copulation lasted 207 minutes in average. There was an evidence that female emit sexual communication signal and male respond to it, and it seemed that the sound production is possibly a part of the courtship behavior of sweet potato leaf worm.

Antiferroelectric Liquid Crystal from Bent-Core Molecule with Vinyl End Group

  • Lee, Chong-Kwang;Kwon, Soon-Sik;Kim, Tae-Sung;Shin, Sung-Tae;Choi, Hong;Choi, E. Joon;Kim, Sea-Yun;Zin, Wang-Choel;Kim, Dae-Choel;Chien, Liang-Chy
    • Bulletin of the Korean Chemical Society
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    • v.25 no.8
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    • pp.1171-1176
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    • 2004
  • Three banana-shaped achiral compounds, 4-chloro-1,3-phenylene bis [4-{4-(undecenyloxy)phenyl imino-methyl} benzoate] derivatives, were synthesized with variation of a substituent (x=H, F, Cl); their antiferro-electric properties are described. The smectic mesophases, including a switchable chiral smectic C(Sm $C^{\ast}$) phase, were characterized by differential scanning calorimetry, polarizing optical microscopy, triangular wave method, and X-ray diffractometry. The presence of vinyl groups at the terminals of linear side wings in the banana-shaped achiral molecules induced a decrease in melting temperature and formation of the switchable Sm $C^{\ast}$ phase in the melt. The smectic phase having a lateral fluorine-substituent at 3-position of the Schiff's base moiety showed antiferroelctric switching, and the value of spontaneous polarization on reversal of an applied electric field was 250 nC/$cm^2$ .

Dual Plane Augmentation Genioplasty Using Gore-Tex Chin Implants

  • Kim, Byung Jun;Lim, Jong Woo;Park, Ji Hoon;Lee, Yoon Ho
    • Archives of Craniofacial Surgery
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    • v.15 no.2
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    • pp.82-88
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    • 2014
  • Background: The chin shape and position is important in determining the general shape of the face, and augmentation genioplasty is performed alone or in combination with other aesthetic procedures. However, augmentation genioplasty using osteotomy is an invasive and complex procedure with the potential to damage mentalis muscle and mental nerve, to affect chin growth, and prolonged recovery. Our aim was to present our experience with a modified augmentation genioplasty procedure for hypoplastic chins using a Gore-Tex implant. Methods: Two vertical slit incisions were made at the canine level to create a supra-periosteal pocket between the incisions, preserving the periosteum and mentalis muscle. Minimal sub-periosteal dissection was performed lateral to the incisions along the mandibular border. The both wings of implant were inserted under the periosteum to achieve a stable dual plane implantation. Results: In total, 47 patients underwent dual plane chin augmentation using a Gore- Tex implant between January 2008 and May 2013. The mean age at operation was 25.77 years (range, 15-55 years). There were 3 cases of infection; one patient was treated with antibiotics, the others underwent implant removal. Additionally, two patients complained of postoperative parasthesia that spontaneously improved without any additional treatment. Most patients were satisfied with the postoperative outcomes, and no chin growth problems were observed among the younger patients. Conclusion: Dual plane Gore-Tex chin augmentation is a minimally-invasive operation that is simple and safe. All implants yielded satisfactory results with no significant complications such as mental nerve injury, lower lip incompetence, or chin growth limitation.

MOLECULAR OUTFLOWS FROM NEWLY FORMED MASSIVE STARS

  • KIM, KEE-TAE;KIM, WON-JU;KIM, CHANG-HEE
    • Journal of The Korean Astronomical Society
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    • v.48 no.6
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    • pp.365-380
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    • 2015
  • We map 6 massive young stellar objects (YSOs) in the CO J=2-1 line and survey 18 massive YSOs, including the six, in the HCO+ J=1−0, SiO J=2−1, H2O 616 − 523 maser, and CH3OH 70 − 61 A+ maser lines. We detect CO bipolar outflows in all the six mapped sources. Four of them are newly discovered (07299−1651, 21306+5540, 22308+5812, 23133+6050), while 05490+2658 is mapped in the CO J=2-1 line for the first time. The detected outflows are much more massive and energetic than outflows from low-mass YSOs with masses >20 M and momenta >300 M km s−1. They have mass outflow rates (3−6)×10−4 M yr−1, which are at least one order of magnitude greater than those observed in low-mass YSOs. We detect HCO+ and SiO line emission in 18 (100%) and 4 (22%) sources, respectively. The HCO+ spectra show high-velocity wings in 11 (61%) sources. We detect H2O maser emission in 13 (72%) sources and 44 GHz CH3OH maser emission in 8 (44%) sources. Of the detected sources, 5 H2O and 6 CH3OH maser sources are new discoveries. 20081+3122 shows high-velocity (>30 km s−1) H2O maser lines. We find good correlations of the bolometric luminosity of the central (proto)star with the mechanical force, mechanical luminosity, and mass outflow rate of molecular outflow in the bolometric luminosity range of 10−1−106 L, and identified 3 intermediate- or high-mass counterparts of Class O objects.