• Title/Summary/Keyword: Main Wing

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A Study of Controversy on Korean Economics and Academic Colonialism of Left-Wing Economics in the 1970~80s (1970-80년대 한국경제학 논쟁과 진보경제학의 학문적 식민주의 연구)

  • Jeong, Seong-gi
    • 사회경제평론
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    • v.31 no.3
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    • pp.93-130
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    • 2018
  • This is the first study of the relation between the controversy on Korean Economics and the controversy on the capitalist social formation of Korea in the 1970-80. The main results of this study is as following: Almost all Korean Economists think 'Korean Economics' do not exist, but korean philosophers think Korean philosophy which is different from western philosophy do exist. So Korean economists tend to believe in the universal validity of western economics. In fact, Some Korean Economists began to argued about universal validity of American-Western economics and making Korean Economics in 1970s, the controversy ceased in the mid of 1980s. Left-wing Economists insisted that the right wing conservetive economics is imported from, mainly, U.S.A, Korea is academic colony of U.S.A. But progressive economics was also imported from Western world, or Soviet Union in the process of controvesy on Korean capitalist social formation in 1980s. It is necessary to retrospect and re-examine the controversy on Korean Economics and on Korean capitalist social formation to develop Economics of Korea.

Anastral Spindle 3/Rotatin Stabilizes Sol narae and Promotes Cell Survival in Drosophila melanogaster

  • Cho, Dong-Gyu;Lee, Sang-Soo;Cho, Kyung-Ok
    • Molecules and Cells
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    • v.44 no.1
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    • pp.13-25
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    • 2021
  • Apoptosis and compensatory proliferation, two intertwined cellular processes essential for both development and adult homeostasis, are often initiated by the mis-regulation of centrosomal proteins, damaged DNA, and defects in mitosis. Fly Anastral spindle 3 (Ana3) is a member of the pericentriolar matrix proteins and known as a key component of centriolar cohesion and basal body formation. We report here that ana3m19 is a suppressor of lethality induced by the overexpression of Sol narae (Sona), a metalloprotease in a disintegrin and metalloprotease with thrombospondin motif (ADAMTS) family. ana3m19 has a nonsense mutation that truncates the highly conserved carboxyl terminal region containing multiple Armadillo repeats. Lethality induced by Sona overexpression was completely rescued by knockdown of Ana3, and the small and malformed wing and hinge phenotype induced by the knockdown of Ana3 was also normalized by Sona overexpression, establishing a mutually positive genetic interaction between ana3 and sona. p35 inhibited apoptosis and rescued the small wing and hinge phenotype induced by knockdown of ana3. Furthermore, overexpression of Ana3 increased the survival rate of irradiated flies and reduced the number of dying cells, demonstrating that Ana3 actively promotes cell survival. Knockdown of Ana3 decreased the levels of both intra- and extracellular Sona in wing discs, while overexpression of Ana3 in S2 cells dramatically increased the levels of both cytoplasmic and exosomal Sona due to the stabilization of Sona in the lysosomal degradation pathway. We propose that one of the main functions of Ana3 is to stabilize Sona for cell survival and proliferation.

Drag Reduction Design for a Long-endurance Electric Powered UAV

  • Jin, Wonjin;Lee, Yung-Gyo
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.2
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    • pp.311-324
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    • 2015
  • This study presents computational analyses for low-drag aerodynamic design that are applied to modify a long-endurance UAV. EAV-2 is a test-bed for a hybrid electric power system (fuel cell and solar cell) that was developed by the Korean Aerospace Research Institute (KARI) for use in future long-endurance UAVs. The computational investigation focuses on designing a wing with a reduced drag since this is the main contributor of the aerodynamic drag. The airfoil and wing aspect ratio of the least drag are defined, the fuselage configuration is modified, and raked wingtips are implemented to further reduce the profile and induced drag of EAV-2. The results indicate that the total drag was reduced by 54% relative to EAV-1, which was a small-sized version that was previously developed. In addition, static stabilities can be achieved in the longitudinal and lateral-directional by this low-drag configuration. A long-endurance flight test of 22 hours proves that the low-drag design for EAV-2 is effective and that the average power consumption is lower than the objective cruise powerof 200 Watts.

Microbial Communities of Activated Sludge Performing Enhanced Biological Phosphorus Removal in a Sequencing Batch Reactor Supplied with Glucose

  • Jeon, Che-Ok;Seung, Han-Woo;Park, Jong-Moon
    • Journal of Microbiology and Biotechnology
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    • v.13 no.3
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    • pp.385-393
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    • 2003
  • Microbial communities were analyzed in an anaerobic/aerobic sequencing batch reactor (SBR) fed with glucose as a sole carbon source. Scanning electron microscopy (SEM) showed that tetrad or cuboidal packet bacteria dominated the microbial sludge. Quinone, slot hybridization, and 165 rRNA gene sequencing analyses showed that the Proteobacteria beta subclass and the Actinobacteria group were the main microbial species in the SBR sludge. However, according to transmission electron microscopy (TEM), the packet bacteria did not contain polyphosphate granules or glycogen inclusions, but only separate coccus-shaped bacteria contained these, suggesting that coccus-shaped bacteria accumulated polyphosphate directly and the packet bacteria played other role in the enhanced biological phosphorus removal (EBPR). Based on previous reports, the Actinobacteria group and the Proteobacteria beta subclass were very likely responsible for acid formation and polyphosphate accumulation, respectively, and their cooperation achieved the EBPR in the SBR operation which was supplied with glucose.

POLARIZATION OF $H_{\alpha}$ WINGS RAMAN-SCATTERED IN SYMBIOTIC STARS (공생별에서의 $H_{\alpha}$날개의 편광연구)

  • BAK JIH-YONG;LEE HEE-WON
    • Publications of The Korean Astronomical Society
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    • v.15 no.spc1
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    • pp.147-151
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    • 2000
  • Symbiotic stars, believed to be binary systems of a mass-losing giant and a white dwarf with an emission nebula, are known to exhibit very broad wings around Hex that extend to $\~10^3km\;s^{-1}$. The wing formation mechanism is not a settled matter and recently Lee (2000) proposed that Raman scattering of Ly$\beta$ by neutral hydrogen is responsible for the broad H$\alpha$ wings. In this model, it is predicted that. the Hex wings will be polarized depending on the geometric and kinematic distribution of the scatterers relative to the UV emission region. In this paper, we investigate the polarization of Hex wings in symbiotic stars. Noting that many symbiotic stars possess bipolar nebular morphology, we assume that the distribution of neutral scatterers follows the similar pattern with a receding velocity of several tens of km $s^{-1}$ that mimics the expansion of the neutral envelope of the nebula. It is found that the red wing is more strongly polarized than the blue and main part and that the polarization direction is along the equatorial plane. We obtain a typical degree of polarization $\~10$ percent, however, it varies depending on the detailed distribution of H I scatterers We conclude that spectropolarimetry will provide very important information on the origin of the Hex wings.

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Structural Development for Human Powered Aircraft (인간동력항공기 구조 개발)

  • Shin, Jeong Woo;Woo, Dae Hyun;Park, Ill Kyung;Lee, Mu-Hyoung;Lim, Joosup;Park, Sang Wook;Kim, Sung Joon;Ahn, Seok Min
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.21 no.1
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    • pp.62-67
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    • 2013
  • Human Powered Aircraft (HPA) should be light in weight and have high efficiency because power source of propulsion is human muscles. Airframe structure takes up most of empty weight of aircraft, so weight reduction of structure is very important issue for HPA. In this paper, design/analysis/test procedures for ultra light weight structure of the HPA developed by Korea Aerospace Research Institute (KARI) are explained briefly. Structural design is conducted through case studies on HPA in the USA and Japan. Loads analysis is performed to calculate design loads which is needed for structural design and analysis. Structural analysis is conducted for structure sizing. Static strength test of main wing spar which is primary structure of wing is performed to verify structural integrity.

Experimental and Numerical Assessment of the Service Behaviour of an Innovative Long-Span Precast Roof Element

  • Lago, Bruno Dal
    • International Journal of Concrete Structures and Materials
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    • v.11 no.2
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    • pp.261-273
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    • 2017
  • The control of the deformative behaviour of pre-stressed concrete roof elements for a satisfactory service performance is a main issue of their structural design. Slender light-weight wing-shaped roof elements, typical of the European heritage, are particularly sensitive to this problem. The paper presents the results of deformation measurements during storage and of both torsional-flexural and purely flexural load tests carried out on a full-scale 40.5 m long innovative wing-shaped roof element. An element-based simplified integral procedure that de-couples the evolution of the deflection profile with the progressive shortening of the beam is adopted to catch the experimental visco-elastic behaviour of the element and the predictions are compared with normative close-form solutions. A linear 3D fem model is developed to investigate the torsional-flexural behaviour of the member. A mechanical non-linear beam model is used to predict the purely flexural behaviour of the roof member in the pre- and post-cracking phases and to validate the loss prediction of the adopted procedure. Both experimental and numerical results highlight that the adopted analysis method is viable and sound for an accurate simulation of the service behaviour of precast roof elements.

A Study on the Application of Machine Simulation and Angle Milling Head of a 6-Axis Parallel Kinematic Machine (6축 병렬기구 공작기계의 머신 시뮬레이션과 앵글밀링헤드 적용에 관한 연구)

  • Lee, In-Su;Kim, Hae-Ji;Kim, Nam-Kyung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.5
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    • pp.47-54
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    • 2017
  • This study examines the implementation of a kinematic machining tool to evaluate the interference and collision phenomenon of 5-axis machining of wing ribs from airplanes, particularly for a large-size model airplane. We develop a machine simulation model of a parallel kinematic machining tool that can operate in a virtual space, which is equivalent to the authentic conditions in the field. The investigation of the simulation function elements indicates the necessity to generate the 6-axis machining, which attaches an angle head to the main axis of the machine. Using an NC program for the wing ribs, we attempt to verify the correspondence and conformity between the machine simulation model and the actual equipment.

The Development and Future Prospect of Pair Trawling in Korean Waters since 1980's (1980년대 이후의 쌍끌이 대형(大型) 기선저인망(機船底引網) 어구(漁具)·어법(漁法)의 발달(發達)과 전망(展望))

  • Lee, Byoung-Gee;Lim, Han-Sup
    • Journal of Fisheries and Marine Sciences Education
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    • v.5 no.2
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    • pp.90-97
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    • 1993
  • Pair trawling is one of the important fishing methods for Korean fisheries, and is working in the western sea of Korea - the Yellow Sea and the East China Sea. On the engine power of the trawlers, 72% of 190 pairs of trawlers were equipped with 450ps class engine, and 21% with 450~750ps and merely 7% with in 750ps class 1980. Thereafter the engine power has grown up, so that 450~750ps occupy 28% and 750ps or more 27% in 1992. Main objective fishes of pair trawling were traditionally flat fishes, so the fundamental shape of pair trawl net was a four - seam net, but by the gradual shortage of flat fishes, roundfishes has been noticed. So the six - seam net which performs high opening of net mouth has been used widely since 1985. In the six - seam net, the length of wing was not so short in the beginning but became short in the later instead of the net pendant elongated, and also the pendant was separated into three pieces according to the change of wing structure. Since the 1990's, the objective fishes has gradually been changed into pelagic fishes, the fishing technique is required to fit the behavior of fishes. So the midwater trawling or the multi -layer trawling became required.

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Parameter Study of Circular Cross-section Wing Spar by Using EDISON Ksec2D-AE (EDISON Ksec2D-AE를 이용한 원형 단면 날개 보의 파라미터 연구)

  • Koo, Sang-Hoon;Ha, Hyeon-Ho
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.175-182
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    • 2016
  • Recently, carbon fiber-reinforced composite is widely used in many aerospace applications. Among most of the aerospace vehicles, human-powered aircraft essentially uses it for minimizing the weight of the vehicle and gaining high stiffness to increase its efficiency. In this paper, main wing spar of the human-powered aircraft is investigated. Finite element models were created based on the baseline model built in 2013 to make analysis of cross-section of the spar with varying ply angles of each layer of the spar. Objective function, which is affected from bending rigidity, torsional rigidity, and strength ratio, was evaluated for every cases. The model of 2013 and present cases were put into comparison by values evaluated from objective function. From the comparison, it was concluded that there are more chances to improve the baseline model to make the vehicle better in stiffness and weight than the model of 2013.

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