• 제목/요약/키워드: EAV

검색결과 51건 처리시간 0.02초

고고도 장기체공 전기 동력 무인기의 꼬리 날개 설계 (Empennage Design of Solar-Electric Powered High Altitude Long Endurance Unmanned Aerial Vehicle)

  • 황승재;이융교;김철완;안석민
    • 한국항공우주학회지
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    • 제41권9호
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    • pp.708-713
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    • 2013
  • 한국항공우주연구원(KARI)은 고고도 전기추진 장기체공 무인기(EAV-3)를 개발하고 있는 중 이다. 우선 고고도 상승 기술 시연을 위한 축소형 비행체 EAV-2H를 개발하였고 EAV-2H로 초도 비행시험을 수행한 결과 측풍에 대한 방향 안정성 및 조종성의 향상이 요구되므로 Advanced Aircraft Analysis(AAA)를 이용한 수직 꼬리날개와 방향타의 재설계를 진행하였다. 방향 조종성을 개선하기위해 방향타의 크기를 기존의 평균 방향타 시위대 수직 꼬리날개 시위 $C_r/C_v(%)=30$$C_r/C_v(%)=60$로 늘려 EAV-2H가 가지는 측풍에 대한 방향 조종성(${\beta}(deg)=25^{\circ}$, $v_1(m/sec)=3.54$)을 개선하였다. 또한, 측풍에 의해 발생하는 측력(side force)의 영향을 최소화하기위해 EAV-2H의 수직미익 크기를 기존 대비 15% 줄여(최소한의 방향 안정성 확보, $Cn_{\beta}=0.0588rad^{-1}$), $C_{y_{\beta}}$는 15% $C_{y_r}$는 22% 감소시킴으로써 측풍이 EAV-2H에 미치는 영향을 최소화 하였다. 설계된 EAV-2H의 꼬리날개의 성능은 비행 시험을 통해 검증하였고 그 결과를 적용하여 고고도 장기체공 전기추진 무인기(EAV-3)의 꼬리날개를 설계하였다.

양도락과 EAV 진단결과(診斷結果)에 대(對)한 상호비교(相互比較) 연구(硏究) -중풍(中風) 환자(患者) 18예(例)를 중심(中心)으로- (The Comparative studies on Diagnostic Results of Yangdorack and EAV -on the 18 Cases of stroke patients-)

  • 박경진;조명래;윤여충
    • Journal of Acupuncture Research
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    • 제15권2호
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    • pp.199-209
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    • 1998
  • We compared and studied the results on two diagnostic machines called Yangdorack and EAV on 18 recovering paralytic patients. The results were as folIows ; 1. Patients with weak motor ability showed an average of 25% fewer units of Yangdorack and an average of 49% fewer units of EAV. 2. Deficiency/excess diagnostic results on meridian and internal organs showed 58.5% deficiency and 41.5% excess on the Yangdorack ; 67.9% of decline-degenerative activity and 32.1% of stimulus-inflarrunation activity on the EAV. 3. In the attack of meridian and internal organs in view of the five elements(五行), in rate of deficiency, decline and degeneration of the fire meridian(火經) in view of the highest rate accounts showed 19.5% on the Yangdorack and 20.4% on the EAV. 4. In comparing deficiency/excess results on the Yangdorack with results of decline-degenerative value and stimulus-inflammation value on the EAV, they both showes a 39% rate. 5. In comparing clinical syndromes on the Yangdorack and common diseases on the EAV, they showed a 72% agreement.

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EAV경락계와 고전침구경락계의 경혈학적 비교.고찰 (Study on Comarison of EAV Measurement Points with Acupuncture Points)

  • 류경주;김정헌
    • 한국한의학연구원논문집
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    • 제1권1호
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    • pp.363-400
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    • 1995
  • The electroacupuncture according to Voll(EAV) is a method of combining the fundamentals of classical acupuncture with the facilities of modern electronics for diagnostics and therapy. Classical acupuncture uses energy conducting lines called 'meridians' and acupuncture points situated along them. Dr. Voll is considered the founder of 'EAV' since he succeeded not only in finding a method of exact electric localization and in explaining the interelation between the acupuncture points and their individual organs, but he also succeeded in measuring the resistance of these points and in explaining the diagnostic meaning of the measured values. In the course of his research, Voll found numerous new measurement points and energy conducting vessels unknown to classical acupuncture, but indispensible for diagnosis of human organic functions. As a basis of modern research in meridian theory, I tried to compare EAV measurement point with classical acupuncture point.

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Optimized Entity Attribute Value Model: A Search Efficient Re-presentation of High Dimensional and Sparse Data

  • Paul, Razan;Latiful Hoque, Abu Sayed Md.
    • Interdisciplinary Bio Central
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    • 제3권3호
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    • pp.9.1-9.5
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    • 2011
  • Entity Attribute Value (EAV) is the widely used solution to represent high dimensional and sparse data, but EAV is not search efficient for knowledge extraction. In this paper, we have proposed a search efficient data model: Optimized Entity Attribute Value (OEAV) for physical representation of high dimensional and sparse data as an alternative of widely used EAV. We have implemented both EAV and OEAV models in a data warehousing en-vironment and performed different relational and warehouse queries on both the models. The experimental results show that OEAV is dramatically search efficient and occupy less storage space compared to EAV.

Aerodynamic Design of the Solar-Powered High Altitude Long Endurance (HALE) Unmanned Aerial Vehicle (UAV)

  • Hwang, Seung-Jae;Kim, Sang-Gon;Kim, Cheol-Won;Lee, Yung-Gyo
    • International Journal of Aeronautical and Space Sciences
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    • 제17권1호
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    • pp.132-138
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    • 2016
  • Korea Aerospace Research Institute (KARI) is developing an electric-driven HALE UAV in order to secure system and operational technologies since 2010. Based on the flight tests and design experiences of the previously developed electric-driven UAVs, KARI has designed EAV-3, a solar-powered HALE UAV. EAV-3 weighs 53kg, the structure weight is 22kg, and features a flexible wing of 19.5m in span with the aspect ratio of 17.4. Designing the main wing and empennage of the EAV-3 the amount of the bending due to the flexible wing, 404mm at 1-G flight condition based on T-800 composite material, and side wind effects due to low cruise speed, $V_{cr}=6m/sec$, are carefully considered. Also, unlike the general aircraft there is no center of gravity shift during the flight because of the EAV-3 is the solar-electric driven UAV. Thus, static margin cuts down to 28.4% and center of gravity moves back to 31% of the Mean Aerodynamic Chord (MAC) comparing with the previously designed the EAV-2 and EAV-2H/2H+ to upgrade the flight performance of the EAV-3.

Computational Analysis of the Aerodynamic Performance of a Long-Endurance UAV

  • Jin, Wonjin;Lee, Yung-Gyo
    • International Journal of Aeronautical and Space Sciences
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    • 제15권4호
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    • pp.374-382
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    • 2014
  • This paper presents the computational aerodynamic analysis of a long-endurance UAV that was developed by the Korea Aerospace Research Institute (KARI), named EAV-2. EAV-2 is a technical demonstrator of aerodynamically efficient design, as well as a hybrid electric-propulsion system for future long-endurance UAVs. We evaluated the aerodynamic characteristics of six low-Reynolds number airfoils, using a panel method code, XFOIL, to select an optimal airfoil for the long-endurance mission of EAV-2. The computational results by a CFD code, FLUENT, suggested that the aerodynamic performance of EAV-2 would be notably improved after adopting SG6043 airfoil, and modifying the fuselage design. This reduced the total drag by 43%, compared to that of a previous KARI model, EAV-1, at the target lift of $C_L=1.0$. Also, we achieved a drag reduction of approximately 14% by means of the low-drag fuselage configuration.

소화불량증에서 호발하는 두통의 위장질환과의 상관성에 대한 임상연구 (A Clinical Study of Correlation Between Frequently Occurring Headache from Gastrointestinal Disorder and Dyspepsia)

  • 최영규;김재관;최서형
    • 대한한의진단학회지
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    • 제14권1호
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    • pp.36-43
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    • 2010
  • Objectives: Since we found patients with dyspepsia as their major symptom had high rate of headache, would like to find out a rational diagnosis ground by using EAV correlation between headache and gastrointestinal disorder Methods: We did survey and EAV inspection on 128 patients came by gastrointestinal disorder who quoted 4 and 5 degree for their headache symptoms) Results & Conclusion The results of this study were as follows: 1. From dyspepsia, we saw higher rate by order of epigastric discomfort, bloating, stomach trouble, bleching, etc. 2. By EAV analysis, found functional deterioration by order of stomach, nerval degeneration vessel, gall bladder/bile duct, liver. 3. By EAV analysis, functional deterioration of stomach, gall bladder/bile duct, liver represent dyspepsia and nerval degeneration vessel represent headache. We found the correlation between dyspepsia and headache by observation at a time.

고고도 장기체공 태양광 무인기 개발 (Developing High Altitude Long Endurance (HALE) Solar-powered Unmanned Aerial Vehicle (UAV))

  • 황승재;김상곤;이융교
    • 항공우주시스템공학회지
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    • 제10권1호
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    • pp.59-65
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    • 2016
  • Korea Aerospace Research Institute (KARI) is developing an electric-driven HALE UAV in order to secure system and operational technologies since 2010. Based on the 5 years of flight tests and design experiences of the previously developed electric-driven UAVs, KARI has designed EAV-3, a solar-powered HALE UAV. EAV-3 weighs 53 kg, the structure weight is 21 kg, and features a flexible wing of 19.5 m in span with the aspect ratio of 17.4. Designing the main wing and empennage of the EAV-3 the amount of the bending due to the flexible wing, 404 mm at 1-G flight condition based on T-800 composite material, and side wind effects due to low cruise speed, V_cr = 6 m/sec, are carefully considered. Also, unlike the general aircraft there is no center of gravity shift during the flight. Thus, the static margin cuts down to 28.4% and center of gravity moves back to 31% of the Mean Aerodynamic Chord (MAC) comparing to the previously developed scale-down HALE UAVs, EAV-2 and EAV-2H, to minimize a trim drag and enhance a performance of the EAV-3. The first flight of the EAV-3 has successfully conducted on the July 29, 2015 and the test flight above the altitude 14 km has efficiently achieved on the August 5, 2015 at the Goheung aviation center.

경락노선상 피부전기 측정기 (EAV, MIR-1) 의 신뢰도 연구 (Reliability of Two Electrodermal Meridian Measurement Systems: EAV and Newly Developed MIR-1)

  • 인창식;허익범;이유정;사공석진;고형균;박영배;이우철
    • 대한한의진단학회지
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    • 제9권1호
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    • pp.125-130
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    • 2005
  • Background and purpose: We evaluated the reliability of two electrodermal measurement devices on meridian skin areas; Electro Acupuncture according to Dr. Voll (EAV) method and newly developed MIR-1. Methods: Eighteen volunteers were tested repeatedly on the same condition with each device. To explore the intra-rater, inter-rater, and test-retest reliabilities, one rater tested each subject twice in succession, then the other rater tested the subject in a row. Finally, retests on the subjects with each device were performed 1 week later. The reliability was determined by Pearson correlation and intraclass correlation statistics. Results: EAV method showed poor reliability, while MIR-1 showed good reliability. Conclusion: It is suggested that further research on the reliability and useful device in both fields of clinical practice and biomedical research.

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비행시험과 전산해석을 통한 소형무인기 항력 예측 (In-Flight and Numerical Drag Prediction of a Small Electric Aerial Vehicle)

  • 진원진;이융교
    • 한국항공운항학회지
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    • 제23권2호
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    • pp.51-56
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    • 2015
  • This paper presents the procedure of drag prediction for EAV-1, based on a numerical analysis correlated to an in-flight test. EAV-1, developed by Korea Aerospace Research Institute, is a small-sized UAV to test a hydrogen-fuel cell power system. The long-endurance test flight of 4.5 hours provides numerous in-flight data. The thrust and drag of EAV-1 during the flight test are estimated based on the wind-tunnel test results for EAV-1's propeller performance. In addition, the CFD analysis using a commercial Navier-Stokes code is carried out for the full-scale EAV-1. The computational result suggests that the initial CFD analysis substantially under-predicts the in-flight drag in that the discrepancy is up to 27.6%. Therefore, additional investigation for more accurate drag prediction is performed; the effect of propeller slipstream is included in the CFD analysis through "fan disk" modelling. Also, the additional drag from airplane trim and load factor that actually exists during the flight test in a circular path is considered. These supplemental analyses for drag prediction turn out to be effective since the drag discrepancy reduces to 2.3%.