• Title/Summary/Keyword: EAV

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Aerodynamic Design of EAV Propeller using a Multi-Level Design Optimization Framework (다단 최적 설계 프레임워크를 활용한 전기추진 항공기 프로펠러 공력 최적 설계)

  • Kwon, Hyung-Il;Yi, Seul-Gi;Choi, Seongim;Kim, Keunbae
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.3
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    • pp.173-184
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    • 2013
  • A multi-level design optimization framework for aerodynamic design of rotary wing such as propeller and helicopter rotor blades is presented in this study. Strategy of the proposed framework is to enhance aerodynamic performance by sequentially applying the planform and sectional design optimization. In the first level of a planform design, we used a genetic algorithm and blade element momentum theory (BEMT) based on two-dimensional aerodynamic database to find optimal planform variables. After an initial planform design, local flow conditions of blade sections are analyzed using high-fidelity CFD methods. During the next level, a sectional design optimization is conducted using two dimensional Navier-Stokes analysis and a gradient based optimization algorithm. When optimal airfoil shape is determined at the several spanwise locations, a planform design is performed again. Through this iterative design process, not only an optimal flow condition but also an optimal shape of an EAV propeller blade is obtained. To validate the optimized propeller-blade design, it is tested in wind-tunnel facility with different flow conditions. An efficiency, which is slightly less than the expected improvement of 7% predicted by our proposed design framework but is still satisfactory to enhance the aerodynamic performance of EAV system.

Morphological characterization of Symbiodinium minutum and S. psygmophilum belonging to clade B

  • Lee, Sung Yeon;Jeong, Hae Jin;Kang, Nam Seon;Jang, Tae Young;Jang, Se Hyeon;Lim, An Suk
    • ALGAE
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    • v.29 no.4
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    • pp.299-310
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    • 2014
  • Dinoflagellates in the genus Symbiodinium are known as zooxanthellae and exist as either symbiotic or free-living forms. Among this genus, two species, Symbiodinium minutum and Symbiodinium psygmophilum, were recently established based on genetic characters. However, some critical morphological characters of these species, such as plate formulae and related diagnoses have not been provided yet. In this study, we analyzed the morphology of S. minutum and S. psygmophilum by scanning and transmission electron microscopy. The S. minutum had the Kofoidian plate formula consisting of a small plate (x), elongated amphiesmal vesicle (EAV), 4', 5a, 8", 7s, two cingulum rows, 18-20c, 6''', and 2'''', while S. psygmophilum had x, EAV, 4', 5a, 8", 7-10s, two cingulum rows, 20-22c, 5-6''', and 1''''. These plate formulae are different from any other reported Symbiodinium species. In addition, both species had a pentagonal 1a plate and a hexagonal 2a plate, while other known Symbiodinium species had a hexagonal 1a plate and a pentagonal 2a plate. Thus, we confirm the species status of S. minutum and S. psygmophilum based on morphological and genetic characters and report the detailed morphological characteristics of these two species.

COMPARISON OF COMMERCIAL AND OPEN SOURCE CFD CODES FOR AERODYNAMIC ANALYSIS OF FLIGHT VEHICLES AT LOW SPEEDS (저속 비행체 공력해석을 위한 상용 및 오픈 소스 CFD 코드 비교)

  • Park, D.H.;Kim, C.W.;Lee, Y.G.
    • Journal of computational fluids engineering
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    • v.21 no.2
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    • pp.70-80
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    • 2016
  • The comparison of two commercial codes(FLUENT and STAR-CCM+) and an open-source code(OpenFOAM) are carried out for the aerodynamic analysis of flight vehicles at low speeds. Tailless blended-wing-body UCAV, main wing and propeller of HALE UAV(EAV-3) are chosen as geometries for the investigation. Using the same mesh, incompressible flow simulations are carried out and the results from three different codes are compared. In the linear region, the maximum difference of lift and drag coefficients of UCAV are found to be less than 2% and 5 counts, respectively and shows good agreement with wind tunnel test data. In a stall region, however, the reliability of RANS simulation is found to become poor and the uncertainty according to code also increases. The effect of turbulence models and meshes generated from different tools are also examined. The transition model yields better results in terms of drag which are much closer to the test data. The pitching moment is confirmed to be sensitive to the existence and the location of transition. For the case of EAV-3 wing, the difference of results with ${\kappa}-{\omega}$ SST model is increased when Reynolds number becomes low. The results for the propeller show good agreement within 1% difference of thrust. The reliability and uncertainty of three codes is found to be reasonable for the purpose of engineering use. However, the physical validity and reliability of results seem to be carefully examined when ${\kappa}-{\omega}$ SST model is used for aerodynamic simulation at low speeds or low Reynolds number conditions.

Forage Performance of Introduced Vetch Cultivars and Korean Native Vetch (도입 베치 품종 및 한국 야생종의 생육특성과 수량)

  • 신정남;김동암;김용원
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.20 no.4
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    • pp.251-258
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    • 2000
  • A field experiment was conducted to evaluate agronomic characteristics, forage quality and dry matter yield of Korean native wild hairy vetch(Vicia villosa Roth) and introduced vetch(Vicia) cultivars from Australia. Seeds were sown on 29 August 1998 and 29 September 1999 at the Livestock Experiment Farm, Keimyung College, Kyeongsan, Kyeongbuk. Vetch plants were harvested on 14 November 1998 and 5 May 1999 and 29 April 2000. 'Haymaker plus' and 'Cappelo woolly pod' (Vicia villosa ssp. dasycarpa(Ten.) Eav.) were higher than 'Namoi' (Vicia villosa ssp. dasycarpa(Ten.) Eav.) in winter survival and 'Popany' (Vicia benghalensis L.) and 'Victa' (Vicia sativa L.) did not overwinter from 1998 to 1999. 'Haymaker plus', 'Cappelo woolly pod', 'Namoi', Korean native wild hairy vetch and Chinese milk vetch were overwintered from 1999 to 2000, except 'Aneto common' (Vicia sativa L.). Fifty percent flowering was observed 23 April for 'Namoi', 24 April for 'Cappelo woolly pod' and 26 April for 'Haymaker plus' from 1998 to 1999. In 1999~2000, fifty percent flowering was observed 12 April for 'Namoi' and 'Cappelo woolly pod', 14 April for 'Haymaker plus', 23 April for Chinese milk, 30 April for 'Aneto common' and Korean native wild hairy vetch. Dry matter yield per hectare was significantly higher(p<0.05) for 'Haymaker plus', 'Cappelo' and 'Namoi' than 'Popany' and 'Vicata' from 1998 to 1999. In 1999-2000, dry matter yield per hectare was higher(p<0.05) for 'Namoi', 'Haymaker plus', 'Cappelo woolly pod' and Korean native wild hairy vetch than Chinese milk vetch (Astragalus sinicus L.) and 'Aneto common'. CP content was relatively high, but Chinese milk vetch and 'Aneto common' were lower than other cultivars. ADF(acid deterguent fiber) was low in Chinese milk vetch, but between the other cultivars were similar. According to the results obtained from this study, it is suggested that 'Haymaker plus' would be recommendable for fall sown vetch for dry matter production.

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Clinical Study On The Remedial Effect of Oriental Medicine Used EAV(Meridian) (EAV(MERIDIAN)을 이용(利用)한 요추간판탈출증(腰椎間板脫出症) 환자(患者)의 한방치료효과에 대한 임상연구(臨床硏究))

  • Chang, Byoung-son;Jin, Kyoung-son;Kim, Jong-wuk;Yang, Myoung-bok;Kim, Il-du;Mun, Hyung-chul;Cho, Eun-hee;Hwang, Woo-jun;Do, Kum-rok
    • Journal of Acupuncture Research
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    • v.19 no.6
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    • pp.80-96
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    • 2002
  • Objective : The Purpose of this Study is to Evaluate Clinical Effect of Oriental Medical Treatment Clinically for the HNP by Comparing the Improvement of VAS and Meridian MAX Score Gap between Common Acupuncture with Sa-am Acupuncture Treatment Group and Common Acupuncture Treatment Group. Methods : The 29 patients who had a Diagnosis of HNP by Lumbar CT and MRI, and were Observed from the first June 2000 to the tenth May 2001, were divided into two classes ; the "A"group was 14 cases practised with Acupuncture treatment used Sa-am Acupuncture with Common Acupuncture, the "B" group 15 cases only Common Acupuncture. Then the time of Discharge, The authors compared VAS(Visual Analogue Scale) and Meridian Max score Gap out of these two groups. Results : On the result of the VAS(Visual Analog Scale), Group "A" is $4.14{\pm}2.62$ and Group "B" us $2.27{\pm}1.94$. So Group "A" is thought to be significance.(Independent T-test, P=0.0399). On the result of the Meridian Max Score Gap, Group "A" is $2.13{\pm}7.29$ and Group "B" is $1.43{\pm}8.42$. So Group "A" proceed more excellent result than the Group "B" Conclusions : The Group with Sa-am Acupuncture and Common Acupuncture treatment is more effective than the Group With Common Acupuncture treatment. And the Group of Done Cox is more effective than the Group of None.

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Comparison of Forage Performance of Introduced Vetch Cultivars and Korean Wild Vetch (자생 베치와 도입 베치의 생육특성과 건물수량 비교)

  • Shin, Chung-Nam;Ko, Ki-Hwan
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.23 no.4
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    • pp.223-228
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    • 2003
  • A field experiment was conducted to evaluate agronomic characteristics, and dry matter yield of Korean wild hairy vetch(Vicia villosa Roth), Korean wild woolly pod vetch(Vicia villosa ssp. dasycarpa(Ten.) Eav.), introduced hairy and woolly pod vetch cultivars from Japan, and Haymaker plus(woolly pod vetch) from Australia. Seeds were sown on 7 October 2000 at the Livestock Experiment Fm, Keimyung College, Seongju, Kyeongbuk. Vetch Plants were harvested on 19 May 2001. Cold tolerance for woolly pod vetch from Japan and Haymaker plus were lower than other cultivars. Dry matter content of the Haymaker Plus was higher than other cultivars. Fifty percent flowering was observed 16 April for Haymaker plus, 20 April fur woolly pod vetch from Japan, 22 April fur Korean wild hairy vetch( I ), 28 April fer Korean wild hairy vetch(II), 1 May for Korean wild hairy vetch(III), 5 May fur Korean wild woolly pod vetch, and 10 May for hairy vetch from Japan. Dry matter yield per hectar was significantly highest(P<0.05) for wild hairy vetch(III) and wild hairy vetch(II) was higher(P<0.05) than other cultivars. Dry matter yield Per hectar was higher(P<0.05) for Haymaker Plus and wild hairy vetch(I) than hairy vetch from Japan.

Measurement of Qi Induced by the Needle Insertion on LI4, LI11 Accupoint using the Oriental Medicine Instruments (인체(人體)의 합곡(合谷) 곡지(曲池) 침자(鍼刺)에 관한 한방진단기기적(韓方診斷機器的) 접근(接近))

  • Jang, K.S.;Na, C.S.;So, C.H.
    • Korean Journal of Oriental Medicine
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    • v.1 no.1
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    • pp.159-178
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    • 1995
  • After acupuncture needles were inserted on apkok(LI4) and Kokchi(LI11) accupoints, physiological changes induced by the varitions of 'Qi' were measured. The body temperature and pulse frequency were fromed to be decreased observed and we presumed that the needle insertion induced some changes of Qi in meridian and this seemed to be achieved by a certain process of Qi induction. We applied EAV, nervinemeter and pulse-taking machine which is widely used as oriental medicine instruments, to the same vounteers and observed the significant variations for each apparatus in spite of partial lack of reproducibility. In this paper, we described about the physical quantity measured by the medical appartatus and how it was related to the variation of Qi The proper conditions used for good oriental medicine instruments have also been suggested.

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Comparative Study on 'Chim Ku' time Therapy and Energy Exchange rule of E.A.V. (침구시간치료(鍼灸時間治療)와 EAV에너지 교환법칙(交換法則)에 관(關)한 비교(比較).고찰(考察))

  • Kim, Jung-Heon;Ryu, Kyung-Joo
    • Korean Journal of Oriental Medicine
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    • v.1 no.1
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    • pp.209-244
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    • 1995
  • The time therapy in oriental medicine is to reserch physiological activity and pathological variation with time, or time with disease. In that, this therapy is to research the development of disease, progress, diagnosis, treatment, and the meaning of preventive medicine. The theory of time therapy has been developed form heaven-human corresponding principle, and fourtimes of seasons is related with human life. After that, this theory affects in yin-yang five circle principle and organ-meridian match system. The independent development was formed later, but the origin has progressed for a logn times. in relation with time therapy, traditional acupuncture therory suggested five semen. In twenty century, the doctor rheinhold voll suggested energy exchange theory, this theory is based on time therapy, but has partial differance also too. His oppinion is this´ the energy present in the body has a circulation following the acupuncture teaching, i.e., the organs and their meridians are flooded in a certain sequence by this flowing energy. This maximum times of the organs are of physiologic and pathologic significance to man. In next time, we will discuss the indivisual theory in detail, and wil have comparison, and considering too.

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Ground Integrated Test for the Hybrid Electric Propulsion System (하이브리드 전기추진 시스템 지상통합시험)

  • Lee, Bo-Hwa;Kim, Young-Mun;Park, Poo-Min;Kim, Keun-Bae;Cha, Bong-Jun
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.772-776
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    • 2011
  • EAV-2, which has a solar cell, fuel cell and battery as its power sources, is under development by KARI. Electric power sources are selected through voltage matching without power converter and controller and tested. The ground integrated test for integrated system is performed during 5 hr. it is confirmed that battery's power response is faster than other power sources at starting and transient condition, fuel cell and solar cell are a major electrical power during cruise condition. It is revealed that the used energy portions of fuel cell, solar cell and battery are 68%, 29%, 2.5% respectively.

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Study on the Development of Meridian Impedance Measurement System (경락 임피던스 측정 시스템 개발에 관한 연구)

  • Lee, Woo-Cheol;Yin, Chang-Shik;Min, Kyoung-Kee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.2
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    • pp.422-429
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    • 2009
  • Meridian which used as the basic theory of acupuncture treatment, is an important functional connection system of acupuncture point in oriental medicine. Yangdorak and EAV have lack of precision because of using 2-electrode method, occurring high non-uniformed current density and electrode contact status on electrode placement spot. Therefore we implemented a meridian impedance measurement system for measuring meridian impedance using 4-electrode method. In order to confirm the precision of developed system, we made an constant current characteristic experiment using standard resistor. As a results of clinical study with 18 subjects, the meridian impedance showed that reproductivity and repeatability of HT7 acupuncture point are $0.515[k{\Omega}]{\pm}0.000$(mean${\pm}$standard deviation) and $0.515[k{\Omega}]{\pm}0.002$, respectively. And reproductivity and repeatability of PC7 are $0.521[k{\Omega}]{\pm}0.000$ and $0.521[{\Omega}]{\pm}0.001$ respectively. The proposed system was stable and reliable. Therefore this study proved AC impedance method to valid in measuring meridian impedance, and also verified precision and repeatability of the proposed meridian impedance measurement system. The proposed system will serve as more effective method of measuring meridian phenomena as a bioelectric signal in clinical practice.