• 제목/요약/키워드: pod characteristics

검색결과 187건 처리시간 0.026초

ALQ-X ECM 포드 비행 적합성 인증 (Flight Compatibility Certification of ALQ-X ECM Pod)

  • 전승문;임재문
    • 한국항공우주학회지
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    • 제33권4호
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    • pp.91-99
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    • 2005
  • ALQ-X ECM 포드를 KF-16D와 RF-4C 항공기에 장착하기 위한 비행적합성 인증을 수행하였다. MIL-HDBK-1763에 부합하는 외부장착 스토어 인증 절차를 계획한 후 유사성 분석, 기존 스토어 질량 및 관성모멘트 분석, 구조해석 및 시험, 지상진동시험 및 플러터해석을 수행하여 비행시험 수행에 대한 안전성을 확인하였다. ALQ-X 장착 형상을 대표하는 비행 형상으로 MIL-HDBK-1763 Test 250 비행시험을 하였다. ALQ-X 장착 전, 후의 비행특성 차이를 분석하여 조종성을 평가 하고 구조건전성과 내구성은 계측데이터를 함께 분석하여 ALQ-X가 KF-16D 및 RF-4C와 적합성이 있음을 확인하였다. 그 결과로서 ALQ-X를 기존에 인증된 ALQ-88 및 ALQ-119와 동일하게 운용할 수 있음을 인증하였다. ALQ-X 비행인증 결과로서 도입 전투기에 대한 TYPE III 비행적합성 인증, 시험데이터를 사용한 플러터 해석 프로그램을 개발, MIL-STD-1553B 데이터버스를 사용한 비행시험 데이터를 획득할 수 있는 기법과 같은 기술적 성과를 거두었다. 본 비행인증 결과는 향후 국내에서 수행할 Type III 형식의 외부장착 스토어 비행인증의 모델케이스가 될 것으로 기대한다.

고기동 항공기 탑재 파드 성능 분석을 위한 모델링 및 시뮬레이션 도구 개발 (Development of Modeling and Simulation Tool for the Performance Analysis of Pods Mounted on Highly Maneuverable Aircraft)

  • 이상현;신진영;이재인;김종범;김송현;김시태;조동현
    • 한국항공우주학회지
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    • 제50권7호
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    • pp.507-514
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    • 2022
  • 전술 표적에 대한 정보를 획득하기 위해 전투기에 탑재하는 EO/IR 정찰용 파드는 일반적으로 항공기 동체 하단에 장착 운영한다. 이러한 외부 장착물을 장착한 항공기는 외부 장착물 없이 비행하는 항공기에 비하여 복잡한 공력 및 관성력 특성을 갖기 때문에 개발 초기에 개발 위험요소를 사전에 식별하여 설계에 반영할 수 있는 시스템 성능 분석 도구가 필수적으로 필요하다. 본 연구에서는 고기동 환경에서 안정적으로 측정 데이터를 획득할 수 있는 파드를 개발하기 위해 필요한 모델링 및 시뮬레이션 도구 개발 방안을 제시하였다. 우선, 고기동 항공기에 탑재한 파드의 한계 운용조건을 도출하고, 한계 운용조건에 따른 탑재 파드의 공력 및 관성 하중을 분석하였으며, 탑재파드를 장착한 항공기의 임무 모사를 통한 비행데이터 생성 및 전송 시스템을 개발하였다.

낙뢰와 대기전계의 탐지를 기반으로 하는 자동낙뢰경보시스템의 구성과 운용특성 (Construction and Operation Characteristics of the Automated Lightning Warning System Based on Detections of Cloud-to-Ground Discharge and Atmospheric Electric Field)

  • 심해섭;이복희
    • 조명전기설비학회논문지
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    • 제27권11호
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    • pp.82-88
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    • 2013
  • It is important to give lightning warning prior to a cloud-to-ground (CG) discharge within an Area of Concern (AOC) because most of lightning damage and victim are usually occurred by the first lightning in the AOC. The aim of this study is to find the optimal operation conditions of the automated lightning warning systems in order to make the best use of the available data. In this paper, the test-operated results of the automated lightning alert and risk management system (ALARM) based on detections of CG discharge and eletrostatic field and optimized at probability of lightning have been described. It was possible to obtain the following warning performance parameters: probability of detection (POD), false alarm ratio (FAR), probability of lightning (POL) and failure-to-warn rate (FTW). The data obtained from trial operation for 5months were not sufficient but the first analysis of domestic lightning warning was carried out. We have observed that the evaluated statistical results through trial operation depend on the various factors such as analysis methods and criteria, topographical conditions, etc. Also we suggest some methods for improvement of POL and POD including the finding of the optimal electric field threshold level to be used, based on the high values of FAR and FTW found in this work.

Morphological diversity in kidney bean(Phaseolus vulgaris L.) germplasm

  • Han, Sea-Hee;Choi, Yu-Mi;Lee, Gi-An;Cho, Yang-Hee;Ma, Kyung-Ho;Lee, Jung-Ro
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.83-83
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    • 2017
  • The National Agrobiodiversity Center (NAS, RDA, Republic of Korea) has continually collected new valuable genetic resources. In this study, we regenerated conserved kidney bean (Phaseolus vulgaris L.) germplasm which couldn't be available because of seed quantity and quality, and we also surveyed their morphological characters for the sustainable utilization. A total of 431 kidney bean accessions were regenerated and 18 morphological traits were surveyed according to the characterization guideline of RDA Genebank. Among the surveyed traits, flowering time ranged from May 23 to September 4 and 73.8% of tested accessions were mainly flowering in June. The maturity time ranged from July 1 to October 15 and main flowering time was July (91.4%). For plant type, 270 accs (62.6%) were climbing type followed by medium type of 86 accs (20.0%) and dwarf type of 65 accs (15.1%). The seed coat colors were various; yellow (34.6%), white (22.3%), brown (17.9%), red (10.7%), black (5.8%), violet (11%), pink (1.4%), navy (0.9%). Principal component analysis indicated that five principal components (PCs) with Eigen values >1 accounted for more than 65.8% variability. The first PC was more related to growth habits such as growth type, flowering time, and plant type. The second and third PCs showed higher values of the pigment characters such as seed coat color, flower color, and pod color. In fourth and fifty PCs, there were the higher positive values of the pod shapes. Our results provided insight into the characteristics kidney beans, thus the utilization basis of kidney beans might be elevated for bio-industry.

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Dry Matter Accumulation, Harvest Index, and Yield of Soybean in Response to Planting Time

  • Chun, Seong-Rak
    • 한국작물학회지
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    • 제47권4호
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    • pp.311-318
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    • 2002
  • Planting date of soybeans [Glycine max (L.) Merr.] is one of production components in cultural systems. The objective of the current study was to identify the components of soybean production and cultural practices encompassing planting dates and cultivars that respond to dry matter accumulation, harvest index and yield components. Three determinate soybean cultivars were planted on May 13 (early), June 3 (mid), and June 24 (late). Planting density was 60$\times$15cm with 2 seeds (222,000 plants per ha). Soybean plants were sampled every 10 days interval from the growth stages of V5 to R8 and separated into leaves including petioles, stems, pods, and seeds. Dry matter accumulations, harvest indices, and yield components were measured. Early planting had taken 55 days from VE to R2 and late planting taken 39 days indicating reduced vegetative growth. Early planting showed higher leaf, stem, pod and seed dry weights than late planting. However, late planting appeared to be higher harvest index and harvesting rate. Vegetative mass including leaf and stem increased to a maximum around R4/R5 and total dry weight increased to a maximum around R5/R6 and then declined slightly at R8. The highest seed yield was obtained with mid planting and no difference was found between early and late plantings. Cultivar differences were found among planting dates on growth characteristics and yield components. The results of this experiment indicated that soybean yield in relation to planting dates examined was mainly associated with harvest index and harvesting rate, and planting date of cultivars would be considered soybean plants to reach the growth stage of R4/R5 after mid August for adequate seed yield.

Occurrence of Sword bean Scab Caused by Cladosporium cucumerinum in Korea

  • Kwon, Jin-Hyeuk;Kang, Soo-Woong;Park, Chang-Seuk
    • Mycobiology
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    • 제28권1호
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    • pp.54-56
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    • 2000
  • A black scab disease occurred on sword bean (Canavalia gladiata) in plastic film houses around Chinju area during the spring season of 1999. The disease started from flower bud, then moved to flower stalk, pod, petiole, cirrus, stem and leaves. The lesions started with small dark brown spots then were gradually expanded. Severely infected plants reached 37.4% of whole plant covered with scab. Numerous conidia were produced on the diseased flower disk, pod, floral axis, stem and leaves. Most of the conidia were appeared to be readily dispersed in the air, but the mycelia were not suggested causing of sooty mold by ectoparasitism. A fungus was isolated from the diseased stem, and inoculated to healthy plants to satisfy the Koch's postulates and proved the fungus was the causal agent of the disease. The isolated fungus grew on potato dextrose agar, forming greenish black to pale brown colonies. Conidia were ellipsoidal, fusiform or subspherical, mostly one-celled but occasionally septated. The conidia were $3.9{\sim}34.1{\times}2.7{\sim}5.1\;{\mu}m$ in size and formed in long branched chains on the erected conidiophores which were pale olivaceous brown and variable in length between $7.2{\sim}210.7\;{\mu}m$ in size. Ramoconidia were $7.6{\sim}29.2{\times}3.2{\sim}14.4\;{\mu}m$ in size. The fungus was identified as Cladosporium cucumerinum based on the above morphological characteristics. The optimum temperature for mycelial growth and conidial formation was about 15 to $25^{\circ}C$. Cladosporium scab of sword bean caused by the fungi has not been reported in Korea previously.

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NACA0015 익형의 압력항력 감소를 위한 인공신경망 기반의 피드백 유동 제어 (Feedback Flow Control Using Artificial Neural Network for Pressure Drag Reduction on the NACA0015 Airfoil)

  • 백지혜;박수형
    • 한국항공우주학회지
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    • 제49권9호
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    • pp.729-738
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    • 2021
  • 본 연구에서는 실속 받음각 근처에 발생하는 익형 위의 유동박리를 억제하기 위하여 인공신경망 기반의 피드백 유동제어를 NACA0015 익형에 수치적으로 적용하였다. 익형 위 박리영역 크기의 축소화라는 제어 목표를 달성하기 위해 익형의 박리 지점 근처에 인위적 외란(Blowing & Suction) 제어 신호를 적용하였다. 유동의 운동을 나타내는 시스템 모델링 단계에서 압력데이터에 적합직교분해(Proper Orthogonal Decomposition)를 적용하여 유동제어에 필요한 운동 모드를 추출하고 유동의 특성을 분석하였다. 분해된 모드를 기반으로 NARX(Nonlinear AutoRegressive Exogenous) 구조의 인공 신경망을 학습하여 유동의 운동을 나타내도록 하였으며, 최종적으로 피드백 제어루프에 작동시켰다. 예측된 제어신호를 CFD 해석에 적용하였으며 제어 유/무에 따른 공력특성을 분석하고 익형 주변의 고유 공간모드의 변화를 비교하여 제어 효과를 분석하였다. 본 연구에서 진행된 피드백 제어는 약 29%의 압력항력 감소효과를 보여주었으며, 이는 익형 뒷전의 큰 압력회복으로 인해 나타나는 것을 확인하였다.

한국 고랭지와 일본에서 채종된 풋콩종자의 생육, 병해 및 수량 비교 (Growth, Disease Damage and Yield of Vegetable Soybean Seeds Produced at Highland of Korea and in Japan)

  • 김홍식;이충식;박은우;홍은희;김석동
    • 한국작물학회지
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    • 제41권3호
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    • pp.257-265
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    • 1996
  • 본 시험은 풋콩 채종기술의 기초자료를 얻고자 미카와시마, 화엄풋콩 및 석량풋콩의 3품종을 1992년 고냉지인 강원도 평창지역에서 생산된 종자와 일본 북해도에서 생산되어 1993년 춘계에 도입된 종자를, 1993년 4월 20일 수원 작물시험장에 채종하여 생육, 병해 및 수량들을 비교 검토한 바 그 주요 결과를 요약하면 다음과 같다. 1. 포장 출현율은 품종간에 차이가 있었고, 채종지간에는 국내고냉지 평창산 종자가 일본산 종자들보다 7% 정도 높았다. 2. 콩 생육경과중에 발생한 미이라병균에 의한 꼬투리 감염, 탄저병, 모자이크바이러스 및 노균병은 채종지간에 차이가 없었다. 3. 채종지간에 풋콩의 생육, 수량구성요소 및 수량성 차이가 없었다. 4. 이상의 결과로서 국내 고냉지에서 풋콩종자를 생산하면 일본산 도입종자에 비하여 출현율이 높고 생육과 수량면에서 저하되지 않는 양질종자의 생산이 가능하다.

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EFFECT OF AGRICULTURAL BY-PRODUCT DIETS ON CARCASS CHARACTERISTICS OF FOUR TYPES OF CATTLE IN THE FEEDLOT

  • Dahlan, I.;Rahman-Haron, A.;Sukri, M.H.I.
    • Asian-Australasian Journal of Animal Sciences
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    • 제5권3호
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    • pp.455-459
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    • 1992
  • Five type of formulated diet from agricultural by-products (ABP) were fed to four breedtype of cattle in feedlot. The ABP used are palm kernel cake (PKC), palm press fibre (PPF), palm oil mill effluent (POME), cocoa pod (COP), coffee pulp (COF) and pineapple waste (PAP). The formulated diets are PS (52% PKC, 15% PPF and 30% POME), PF (57% PKC, 20% PPF and 20% POME), PA (2% PKC and 55% PAP), CO (42% PKC and 55% COP) and CF (67% PKC and 30% COF) with 1% urea, 1% NaCl and 1% vitamins premix. The cattle breedtypes are Kedah-Kelantan (KK), Brahman-KK (BK), Hereford-KK (HK) and Sahiwal-Friesian (SF). The result showed that breedtype significantly affect all the carcass characteristic except dressing percentage. Each breedtype has it's specific carcass characteristics. HK cattle gave high marbling, BK has high % of carcass bone, KK has high % of carcass meat and low % of carcass fat (lean meat type) and SF has high % of carcass fat. Diet-type significantly affect the deposition of fat in the carcass. High moisture diets (PA and CO) produced significantly higher % carcass bone, the lowest % carcass fat and the highest % carcass meat (65.3%). PF, CF, PA and CO diets produced 63.4%, 59.9%, 55.3% and 54.1% carcass meat respectively.

문풀 내 압력 변동에 대한 POD 분석 (Proper Orthogonal Decomposition of Pressure Fluctuations in Moonpool)

  • 이상봉;한범우;박동우;안유원;고석천;서흥원
    • 대한조선학회논문집
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    • 제49권6호
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    • pp.484-490
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    • 2012
  • Experiments of circulating water channel and two dimensional numerical simulations were performed to investigate the fluctuating characteristics of pressure in moonpool. Based on the quasi-two dimensional characteristics of pressure fluctuations disclosed by the spatial cross-correlations, the numerical results showed qualitatively good agreement with experimental data. Proper orthogonal decomposition was employed to the spatial distributions of pressure fluctuations in order to find the first and second modes of fluctuations. The first mode of pressure fluctuations showed that the fluctuating characteristics of pressure were related to the behaviors of vortical structures. The velocity fluctuations were conditionally averaged to make clear that the coherent structures were responsible for the pressure fluctuations in moonpool.