• 한국균학회지
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• 제20권3호
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• pp.216-221
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• 1992

사철느타리버섯, 느타리버섯, 여름느타리버섯 형질전환주(形質轉煥珠)에서 crystal이 형성(形成) 되었으며, crystal은 물에는 녹지않고 고온(高溫)이나 ethanol에 녹으며 ethanol이 휘발되면 재결정이 이루어졌다 . crystal은 고체(固體)배지뿐 아니라 액체(液體) 배지(培地)에서도 형성(形成)되며 균사(菌絲)를 $15-25^{\circ}C$에서 배양(培養)할때 형성(形成)되나 $30-35^{\circ}C$ 에서는 형성(形成)되지 않았다. 또한 uv 를 이용(利用)하여 돌연변이(突然變異)를 유발(誘發)시켰을때도 여름느타리 버섯과 느타리버섯의 1핵(核) 균사(菌絲)에서 crystal을 형성(形成)하는 균주(菌株)를 얻었다 .

• International Journal of Aeronautical and Space Sciences
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• 제15권3호
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• pp.219-231
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• 2014

We develop a preliminary design optimization procedure in this paper regarding the wing planform in a solar-powered high-altitude long-endurance unmanned aerial vehicle. A high-aspect-ratio wing has been widely adopted in this type of a vehicle, due to both the high lift-to-drag ratio and lightweight design. In the preliminary design, its characteristics need to be addressed correctly, and analyzed in an appropriate manner. In this paper, we use the three-dimensional Euler equation to analyze the wing aerodynamics. We also use an advanced structural modeling approach based on a geometrically exact one-dimensional beam analysis. Regarding the structural integrity of the wing, we determine detailed configuration parameters, specifically the taper ratio and the span length. Next, we conduct a multi-objective optimization scheme based on the response surface method, using the present baseline configuration. We consider the structural integrity as one of the constraints. We reduce the wing weight by approximately 25.3 % from that in the baseline configuration, and also decrease the power required approximately 3.4 %. We confirm that the optimized wing has sufficient flutter margin and improved static longitudinal/directional stability characteristics, as compared to those of the baseline configuration.

• 한국한의학연구원논문집
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• 제10권1호
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• pp.119-126
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• 2004

For the purpose of developing new anti-HIV agents from natural sources, the extracts of Solanum nigrum L. were tested for their inhibitory effects on HIV-1 replication and its essential enzymes as the reverse transcriptase (RT), protease and ${\alpha}$-glucosidase. In the assay of HIV-1-infected human T-cell line, water extracts inhibited the HIV- 1 -induced cytopathic effects with IC (inhibitory concentration) of 100 ug/ml. Moreover water extracts (100ug/ml) of aerial parts showed strong activity of 32.6% on anti-HIV-1 PR using the activity of the enzyme to cleave an oligopeptide. In the HIV-1 reverse transcriptase inhibition assay, aqueous extract a inhibited 17.4%, but no glucosidase inhibitory activities. We found out this result, for these samples it is possible that the inhibition of the viral replication in vitro is due to the inhibition at least one of PR and RT. It would be of great interest to identify the compounds which are responsible for this inhibition, since all therapeutically useful agent up to date are PR, RT and ${\alpha}$-glucosidase inhibitors.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 학술대회
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• pp.166-170
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• 2008

The changing process from hovering mode to transition one is of importance to determine a stability of tilt-rotor aircraft, which is utilized in UAV(Unmaned Aerial Vehicle). The analysis on fluid flows and aerodynamic characteristics according to variation of tilting angle of rotor is essential step in development of tilt-rotor. In the present study, the computation domain is divided into the rotating and stationary regions in order to consider the rotating blades. For the convenient realization of various tilting angle as well as application of boundary condition, the whole computation region is constructed into sphere domain. The near farfield boundary condition is adopted. The airfoil used in computation is NACA 0012. The computation results for the hovering mode are validated by comparing with previously conducted experimental results. From the results, the flow fields around rotor blade and the aerodynamic characteristics in transition mode are observed. The computational result will provide the basis for development and performance evaluation of tilt-type aircraft.

• 항공우주시스템공학회지
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• 제10권1호
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• pp.43-50
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• 2016

In order to suggest the optimal manufacturing technology of composite wings of solar-powered unmanned aerial vehicles, this study compared forming technologies to reduce wing weight for long-endurance flight and to improve the manufacturing process for cost-saving and mass production. It compared the manufacturing time and weight of various composite wing molding technologies, including cocuring, secondary bonding, and manufacturing by balsa. As a result, wing weight was reduced through cocuring methods such as band type composite fiber/tape lamination technology, which enabled prolonged flight duration. In addition, the reduced manufacturing time led to a lower cost, which is a good example of weight lightening for not only small solar-powered UAVs, but also composite aircraft.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.55.2-55.2
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• 2011

This research aims to study the effects of the incidence angle and surface temperature on the power generation performance of a thin-film CIGS solar cell for solar powered unmanned aerial vehicles (UAVs). The test rig consists of a unit CIGS solar cell is installed on a table whose angle is controlled manually. A K-type thermocouple is attached to the solar cell surface for temperature measurements. A solar module analyzer measures the voltage and current generated from the test solar cell. The solar module analyzer also calculates the maximum solar power and efficiency of the solar cell. All test data are acquired in a PC. Test results show that the solar cell efficiency decreases significantly with increasing incidence angle and increasing surface temperature in general. As the incidence angle increases from 0 degree to 90 degree, the solar cell efficiency decreases by 60%. The solar cell efficiency decreases by 10% with increasing solar cell surface temperature from $20^{\circ}C$ to $30^{\circ}C$, for exmaple. The direct cooling method of the solar cell using dry ice decreases dramatically the solar cell surface temperature, thus increasing the solar cell efficiency by 15%.

• International Journal of Aeronautical and Space Sciences
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• 제9권1호
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• pp.100-110
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• 2008

It is not easy to monitor and identify all engine faults and conditions using conventional fault detection approaches like the GPA (Gas Path Analysis) method due to the nature and complexity of the faults. This study therefore focuses on a model based diagnostic method using Neural Network algorithms proposed for fault detection on a turbo shaft engine (PW 206C) selected as the power plant for a tilt rotor type unmanned aerial vehicle (Smart UAV). The model based diagnosis should be performed by a precise performance model. However component maps for the performance model were not provided by the engine manufacturer. Therefore they were generated by a new component map generation method, namely hybrid method using system identification and genetic algorithms that identifies inversely component characteristics from limited performance deck data provided by the engine manufacturer. Performance simulations at different operating conditions were performed on the PW206C turbo shaft engine using SIMULINK. In order to train the proposed BPNN (Back Propagation Neural Network), performance data sets obtained from performance analysis results using various implanted component degradations were used. The trained NN system could reasonably detect the faulted components including the fault pattern and quantity of the study engine at various operating conditions.

• 한국통신학회논문지
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• 제35권11B호
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• pp.1732-1737
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• 2010

현재 군에서 무인기를 운용하는 주목적 중 하나는 적에 대한 감시/정찰이다. 이를 위해 무인기는 정보감시/정찰(ISR) 장비들을 탑재하여, 감시/정찰 대상에 대한 영상 데이터를 획득한 후 지상통제소로 전송한다. 지상통제소는 전송된 영상 데이터를 수신한 후, 다양한 사용자에게 배포하게 되는 데, 이 때 품질 보장을 유지하는 것이 중요하다. 본 논문에서는 DDS 표준 프로토콜을 사용하여 무인기의 영상전송 및 품질보장을 관리하는 방안을 제시하였다. 이에 대해 H.264 및 JPEG2000 영상 데이터를 이용하여 영상전송 실험결과 DDS 표준이 UAS 운용에 활용 가능함을 보였다.

• Journal of Plant Biology
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• 제14권3호
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• pp.1-20
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• 1971

Ecological factors limiting Stipa pulchra have been determined in experimental gardens and at several sites in the hills south and east of Monterey, California. The Stipa pulchrafacies of Valley Grassland communities were found to be dominated by that species, though a total of 36 grasses and forbs were collected and identified. Basal area was not large, but aerial cover by Stipa alone averaged over 50 per cent. Across an ecotone between a Stipa association and the California Annual Type a sudden and dramatic change was recorded. Soil measurements there, and in other nearby areas, showed a much higher clay content with more available water and elemental phosphorus at the Stipa sites. Germination of Stipa seeds was high under all laboratory and field conditions, though growth of seeldings was highly variable. Seedlings grown in Stipa woil with an abundance of water were vigorous and reached anthesis the first year. In other soils they grew less, and when grown in competition with Avena fatua they scarcely grew at all. These findings indicate that when established on desirable soils, Stipa competes well and apparently precludes the dominance of Avena fatua and other large annual grasses. On the other hand, because of a lack of vigor in its seedlings, Stipa cannot reinvade the rich more friable soils on which it was once found, and on which it was shown to grow satisfactorily. This supports the contention that Sipa pulchra was the dominant grass through much of the Valley Grassland and Foothill Woodland, but also indicates that well-drained soils and those poor in mineral nutrients probalby never supported such associations.

• Journal of Ginseng Research
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• 제4권1호
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• pp.65-71
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• 1980

Twin-bud seedlings and four-leaflet seedlings of ginseng were found and transplanted to field and their growth characteristics were investigated. 1. Appearance frequencies of twin-bud and four-leaflet seedlings were 0.3 and 0.4 percent, respectively, in common nursery bed: and were 6.6 and 28.4 percent, respectively, in polystem line. 2. Generally, the growth of twin.bud and four-leaflet seedlings were better than those of common seedlings both in aerial part and in root. Root weights of both type seedlings exceeded the common ones by 66 and 38 percent, respectively. 3. When they became two-year-old plants, leafiet number of common plant was 11.6, and those of twin-bud and four-leaflet-seedling plants were 18.1 and 13.8, respectively. There were no inflorescence in twin-bud-seedling plant, but the ratios of in florescent Plant in four-leaflet.seedling and common plant were 44.0 and 12.5 percent, respectively. 4. In two-year-old plant, root weights of twin-bud and four-leaflet-seedling plants were heavier than those of common ones by 27 and 20 percent, respectively.